[PATCH] x86-64: Merge msr.c with i386 version

The only difference was the inline assembly, so move that into
asm/msr.h and merge with the i386 version.

This adds some missing sysfs support code to x86-64.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>