x86: AMD microcode patch loading support

This patch introduces microcode patch loading for AMD
processors. It is based on previous corresponding work
for Intel processors.

It hooks into the general patch loading module. Main
difference is that a container file format is used to hold
all patch data for multiple processors as well as an
equivalent CPU table, which comes seperately, as opposed
to Intel's microcode patching solution.

Kconfig and Makefile have been changed provice config
and build option for new source file.

Signed-off-by: Peter Oruba <peter.oruba@amd.com>
Cc: Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>