crossgcc: Fix building with texinfo-5.x

If you have a recent version of texinfo installed, building the reference
toolchain fails with the following error:
(in util/crossgcc/build-gcc/crossgcc-build.log)

[...]/gcc-4.7.2/gcc/doc/cppopts.texi:806: @itemx must follow @item

Looks like a warning-became-an-error problem in texinfo, to me. Fix that by
making every erroneous @itemx an @item.

Change-Id: I685ae1ecfee889b7c857b148cfab7411a10e7ecd
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: http://review.coreboot.org/2939
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Idwer Vollering <vidwer@gmail.com>

util/crossgcc/patches/gcc-4.7.2_texinfo.patch

@@ -0,0 +1,98 @@
+diff -urp gcc-4.7.2/gcc/doc/cppopts.texi gcc-4.7.2/gcc/doc/cppopts.texi
+--- gcc-4.7.2/gcc/doc/cppopts.texi	2013-03-28 13:41:01.000000000 +0100
++++ gcc-4.7.2/gcc/doc/cppopts.texi	2013-03-28 13:55:05.000000000 +0100
+@@ -803,7 +803,7 @@ Replacement:      [    ]    @{    @}
+ Enable special code to work around file systems which only permit very
+ short file names, such as MS-DOS@.
+ 
+-@itemx --help
++@item --help
+ @itemx --target-help
+ @opindex help
+ @opindex target-help
+diff -urp gcc-4.7.2/gcc/doc/generic.texi gcc-4.7.2/gcc/doc/generic.texi
+--- gcc-4.7.2/gcc/doc/generic.texi	2011-12-23 23:07:16.000000000 +0100
++++ gcc-4.7.2/gcc/doc/generic.texi	2013-03-28 14:01:19.000000000 +0100
+@@ -1415,13 +1415,13 @@ generate these expressions anyhow, if it
+ not matter.  The type of the operands and that of the result are
+ always of @code{BOOLEAN_TYPE} or @code{INTEGER_TYPE}.
+ 
+-@itemx POINTER_PLUS_EXPR
++@item POINTER_PLUS_EXPR
+ This node represents pointer arithmetic.  The first operand is always
+ a pointer/reference type.  The second operand is always an unsigned
+ integer type compatible with sizetype.  This is the only binary
+ arithmetic operand that can operate on pointer types.
+ 
+-@itemx PLUS_EXPR
++@item PLUS_EXPR
+ @itemx MINUS_EXPR
+ @itemx MULT_EXPR
+ These nodes represent various binary arithmetic operations.
+diff -urp gcc-4.7.2/gcc/doc/invoke.texi gcc-4.7.2/gcc/doc/invoke.texi
+--- gcc-4.7.2/gcc/doc/invoke.texi	2012-09-14 22:45:27.000000000 +0200
++++ gcc-4.7.2/gcc/doc/invoke.texi	2013-03-28 13:55:57.000000000 +0100
+@@ -5179,7 +5179,7 @@ thus dbg_cnt() returns true always unles
+ e.g. With -fdbg-cnt=dce:10,tail_call:0
+ dbg_cnt(dce) will return true only for first 10 invocations
+ 
+-@itemx -fenable-@var{kind}-@var{pass}
++@item -fenable-@var{kind}-@var{pass}
+ @itemx -fdisable-@var{kind}-@var{pass}=@var{range-list}
+ @opindex fdisable-
+ @opindex fenable-
+@@ -5327,11 +5327,11 @@ Dump after duplicating the computed goto
+ @option{-fdump-rtl-ce3} enable dumping after the three
+ if conversion passes.
+ 
+-@itemx -fdump-rtl-cprop_hardreg
++@item -fdump-rtl-cprop_hardreg
+ @opindex fdump-rtl-cprop_hardreg
+ Dump after hard register copy propagation.
+ 
+-@itemx -fdump-rtl-csa
++@item -fdump-rtl-csa
+ @opindex fdump-rtl-csa
+ Dump after combining stack adjustments.
+ 
+@@ -5342,11 +5342,11 @@ Dump after combining stack adjustments.
+ @option{-fdump-rtl-cse1} and @option{-fdump-rtl-cse2} enable dumping after
+ the two common sub-expression elimination passes.
+ 
+-@itemx -fdump-rtl-dce
++@item -fdump-rtl-dce
+ @opindex fdump-rtl-dce
+ Dump after the standalone dead code elimination passes.
+ 
+-@itemx -fdump-rtl-dbr
++@item -fdump-rtl-dbr
+ @opindex fdump-rtl-dbr
+ Dump after delayed branch scheduling.
+ 
+@@ -5391,7 +5391,7 @@ Dump after the initialization of the reg
+ @opindex fdump-rtl-initvals
+ Dump after the computation of the initial value sets.
+ 
+-@itemx -fdump-rtl-into_cfglayout
++@item -fdump-rtl-into_cfglayout
+ @opindex fdump-rtl-into_cfglayout
+ Dump after converting to cfglayout mode.
+ 
+@@ -5421,7 +5421,7 @@ Dump after removing redundant mode switc
+ @opindex fdump-rtl-rnreg
+ Dump after register renumbering.
+ 
+-@itemx -fdump-rtl-outof_cfglayout
++@item -fdump-rtl-outof_cfglayout
+ @opindex fdump-rtl-outof_cfglayout
+ Dump after converting from cfglayout mode.
+ 
+@@ -5433,7 +5433,7 @@ Dump after the peephole pass.
+ @opindex fdump-rtl-postreload
+ Dump after post-reload optimizations.
+ 
+-@itemx -fdump-rtl-pro_and_epilogue
++@item -fdump-rtl-pro_and_epilogue
+ @opindex fdump-rtl-pro_and_epilogue
+ Dump after generating the function prologues and epilogues.
+