Pull x86 fixes from Ingo Molnar:
"This contains two fixes: a boot fix for older SGI/UV systems, and an
APIC calibration fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tsc: Read all ratio bits from MSR_PLATFORM_INFO
x86/platform/UV: Bring back the call to map_low_mmrs in uv_system_init