x86,mce: consolidate AMD mcheck initialization

x86,mce: consolidate AMD mcheck initialization

amd_k8.c did a lot of common work and very little K8
specific work. So merge init functions of amd_f10.c and
amd_k8.c and move it into the common amd_mcheck_init
handler. With that done, there is not much left in either
files, so fold all code into just one file - mce_amd.c

While at it, update the comments regarding documentation
with correct URL's and revision numbers.

Also, update copyright info.

Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrishnan@amd.com>
Acked-by: Christoph Egger <chegger@amazon.de>