x86-32, amd: Move va_align definition to unbreak 32-bit build

hpa reported that dfb09f9b7a breaks 32-bit
builds with the following error message:

/home/hpa/kernel/linux-tip.cpu/arch/x86/kernel/cpu/amd.c:437: undefined
reference to `va_align'
/home/hpa/kernel/linux-tip.cpu/arch/x86/kernel/cpu/amd.c:436: undefined
reference to `va_align'

This is due to the fact that va_align is a global in a 64-bit only
compilation unit. Move it to mmap.c where it is visible to both
subarches.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1312633899-1131-1-git-send-email-bp@amd64.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/mm/mmap.c

@@ -31,6 +31,10 @@
 #include <linux/sched.h>
 #include <asm/elf.h>
 
+struct __read_mostly va_alignment va_align = {
+	.flags = -1,
+};
+
 static unsigned int stack_maxrandom_size(void)
 {
 	unsigned int max = 0;
@@ -42,7 +46,6 @@ static unsigned int stack_maxrandom_size(void)
 	return max;
 }
 
-
 /*
  * Top of mmap area (just below the process stack).
  *