ARM: Tell the linker memset and memcpy are functions.

The memset and memcpy functions are assembled as ARM code, likely because
that's the default of the assembler. Without special annotation, the assembler
and linker don't know that those symbols are functions which need special
handling so that ARM/thumb issues are handled properly. This change adds that
annotation which gets those functions working in Coreboot which is compiled as
thumb. Libpayload and depthcharge are compiled as ARM so they don't *need* the
annotation since it just works out in ARM mode, but it's the safe thing to do
in case we change that in the future.

We should explicitly select ARM vs. thumb when assembling assembly files to be
consistent across builds and toolchains.

Change-Id: I814b137064cf46ae9e2744ff6c223b695dc1ef01
Signed-off-by: Gabe Black <gabeblack@chromium.org>
Reviewed-on: http://review.coreboot.org/3672
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

payloads/libpayload/arch/armv7/memcpy.S

@@ -57,6 +57,7 @@
 
 /* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
 
+.type memcpy, function
 .globl memcpy
 memcpy:
 

payloads/libpayload/arch/armv7/memset.S

@@ -27,6 +27,7 @@
  * memset again.
  */
 
+.type memset, function
 .globl memset
 memset:
 	ands	r3, r0, #3		@ 1 unaligned?

src/arch/armv7/memcpy.S

@@ -57,6 +57,7 @@
 
 /* Prototype: void *memcpy(void *dest, const void *src, size_t n); */
 
+.type memcpy, function
 .globl memcpy
 memcpy:
 

src/arch/armv7/memset.S

@@ -27,6 +27,7 @@
  * memset again.
  */
 
+.type memset, function
 .globl memset
 memset:
 	ands	r3, r0, #3		@ 1 unaligned?