i386: Use global flag to disable broken local apic timer on AMD CPUs.

The Averatec 2370 and some other Turion laptop BIOS seems to program the
ENABLE_C1E MSR inconsistently between cores. This confuses the lapic
use heuristics because when C1E is enabled anywhere it seems to affect
the complete chip.

Use a global flag instead of a per cpu flag to handle this.
If any CPU has C1E enabled disabled lapic use.

Thanks to Cal Peake for debugging.

Cc: tglx@linutronix.de
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>