x86 bootblock: improve clang compatibility

Its linker doesn't like "." arithmetics, so use .org,
while its assembler doesn't like data32 prefixes.

Change-Id: I3f5bbb350493d6510b8013df15d44c44c5db63c7
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/4714
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>

src/cpu/x86/16bit/entry16.inc

@@ -105,7 +105,7 @@ _start:
 	lidt	%cs:(%bx)
 	movw	$gdtptr16_offset, %bx
 	subw	%ax, %bx
-	data32  lgdt %cs:(%bx)
+	lgdtl	%cs:(%bx)
 
 	movl	%cr0, %eax
 	andl	$0x7FFAFFD1, %eax /* PG,AM,WP,NE,TS,EM,MP = 0 */
@@ -116,7 +116,7 @@ _start:
 	movl	%ebp, %eax
 
 	/* Now that we are in protected mode jump to a 32 bit code segment. */
-	data32	ljmp	$ROM_CODE_SEG, $__protected_start
+	ljmpl	$ROM_CODE_SEG, $__protected_start
 
 	/**
 	 * The gdt is defined in entry32.inc, it has a 4 Gb code segment

src/cpu/x86/16bit/reset16.inc

@@ -10,7 +10,7 @@ reset_vector:
 	 * instead of the weird 16 bit relocations that binutils does not
 	 * handle consistenly between versions because they are used so rarely.
 	 */
-	. = 0x8;
+	.org 0x8;
 	.code32
 	jmp	protected_start
 	.previous