x86, amd: Include elf.h explicitly, prepare the code for the module.h split

When the moduleu.h splitting tree is merged to the latest
tip:x86/cpu tree, the x86_64 allmodconfig build fails like this:

arch/x86/kernel/cpu/amd.c: In function 'bsp_init_amd':
arch/x86/kernel/cpu/amd.c:437:3: error: 'va_align' undeclared (first use in this function)
arch/x86/kernel/cpu/amd.c:438:23: error: 'ALIGN_VA_32' undeclared (first use in this function)
arch/x86/kernel/cpu/amd.c:438:37: error: 'ALIGN_VA_64' undeclared (first use in this function)

This is caused by the module.h split up intreacting with commit
dfb09f9b7ab0 ("x86, amd: Avoid cache aliasing penalties on AMD
family 15h") from the tip:x86/cpu tree.

I have added the following patch for today (this, or something
similar, could be applied to the tip tree directly - the
export.h include below was added by the module.h splitup).

So include elf.h to use va_align and remove this implicit
dependency on module.h doing it for us.

Signed-off-by: Stephen Rothwell <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Paul Gortmaker <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/kernel/cpu/amd.c

···
 #include <linux/init.h>
 #include <linux/bitops.h>
+#include <linux/elf.h>
 #include <linux/mm.h>
 
 #include <linux/io.h>