i386: Move from explicit ADDR32/DATA32 prefixes to instruction suffixes.

Is more portable.
Binary is unchanged (verified).

grub-core/kern/i386/pc/startup.S

@@ -135,7 +135,7 @@ LOCAL(prot_to_real_addr):
 
 	.macro REAL_TO_PROT
 	movl	LOCAL(real_to_prot_addr), %eax
-	DATA32	call	*%ax
+	calll	*%eax
 	.endm
 
 /*

grub-core/kern/i386/realmode.S

@@ -54,7 +54,7 @@ protstack:
 	.endm
 
 	.macro REAL_TO_PROT
-	DATA32	call	real_to_prot
+	calll	real_to_prot
 	.endm
 
 /*
@@ -137,7 +137,7 @@ real_to_prot:
 	/* load the GDT register */
 	xorw	%ax, %ax
 	movw	%ax, %ds
-	DATA32	ADDR32	lgdt	gdtdesc
+	ADDR32 lgdtl	gdtdesc
 
 	/* turn on protected mode */
 	movl	%cr0, %eax
@@ -145,7 +145,7 @@ real_to_prot:
 	movl	%eax, %cr0
 
 	/* jump to relocation, flush prefetch queue, and reload %cs */
-	DATA32	ljmp	$GRUB_MEMORY_MACHINE_PROT_MODE_CSEG, $protcseg
+	ljmpl	$GRUB_MEMORY_MACHINE_PROT_MODE_CSEG, $protcseg
 
 	.code32
 protcseg:
@@ -237,7 +237,7 @@ tmpcseg:
 	movl	%eax, %cr0
 
 	/* flush prefetch queue, reload %cs */
-	DATA32	ljmp	$0, $realcseg
+	ljmpl	$0, $realcseg
 
 realcseg:
 	/* we are in real mode now
@@ -258,6 +258,6 @@ realcseg:
 #endif
 
 	/* return on new stack! */
-	DATA32	ret
+	retl
 
 	.code32