x86: major refactoring

Refactored code by introducing a two-module solution.

There is one general module in which vendor specific modules can hook into.
However, that is exclusive, there is only one vendor specific module
allowed at a time. A CPU vendor check makes sure only the correct
module for the underlying system gets called.

Functinally in terms of patch loading itself there are no changes. This
refactoring provides a basis for future implementations of other vendors'
patch loaders.

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>

include/asm-x86/microcode.h

@@ -1,3 +1,6 @@
+extern int microcode_init(void *opaque, struct module *module);
+extern void microcode_exit(void);
+
 struct microcode_ops {
 	long (*get_next_ucode)(void **mc, long offset);
 	long (*microcode_get_next_ucode)(void **mc, long offset);