x86: ucode-amd: Load ucode-patches once and not separately of each CPU

This also implies that corresponding log messages, e.g.

  platform microcode: firmware: requesting amd-ucode/microcode_amd.bin

show up only once on module load and not when ucode is updated
for each CPU.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: dimm <dmitry.adamushko@gmail.com>
LKML-Reference: <20091110110723.GH30802@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>