x86: process fam 10h like k8 with fixed mtrr setting

otherwise fixed MTRR for family 10h may not be changed.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>