[PATCH] x86_64: Don't enable ATI apicmaintimer workaround when the machine has C2 or C3
Many laptops have problems with ticking the local APIC timer in C2/C3.
The code added earlier to use it by default on ATI didn't really work
for them. Don't enable it when the system supports C2/C3.
This doesn't fix the problem fully, but at least it's not worse than before.