x86, microcode, amd: Another early loading fixup

commit cd1c32ca969ebfd65e61312c988223bb14f09c2e is an early premature
rendition of the patch. Augment it with this delta patch to:
  * correctly mark offset and size of the matching bin file
  * use __pa instead of __pa_nodebug during AP load
  * check for !initrd_start before using it

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/20130620152414.GA6676@jshin-Toonie
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>