x86/microcode: Correct CPU family related variable types

x86/microcode: Correct CPU family related variable types

Change the type of variables and function prototypes to be in
alignment with what the x86_*() / __x86_*() family/model
functions return.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433436928-31903-21-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>