Revert "x86, mce: do not compile mcelog message on AMD"

This reverts commit 22223c9b, as
requested by Andi Kleen:

  "Obviously kernels compiled with AMD support can still run on non AMD
   systems, so messages like this can never be removed at compile time."

Requsted-by: Andi Kleen <andi@firstfloor.org>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>