x86, amd: Fix panic on AMD CPU family 0x15

x86, amd: Fix panic on AMD CPU family 0x15

[The mainline kernel doesn't have this problem. Commit "(23588c3) x86,
amd: Add support for CPUID topology extension of AMD CPUs" removed the
family check. But 2.6.32.y needs to be fixed.]

This CPU family check is not required -- existence of the NodeId MSR
is indicated by a CPUID feature flag which is already checked in
amd_fixup_dcm() -- and it needlessly prevents amd_fixup_dcm() to be
called for newer AMD CPUs.

In worst case this can lead to a panic in the scheduler code for AMD
family 0x15 multi-node AMD CPUs. I just have a picture of VGA console
output so I can't copy-and-paste it herein, but the call stack of such
a panic looked like:

  do_divide_error
  ...
  find_busiest_group
  run_rebalance_domains
  ...
  apic_timer_interrupt
  ...
  cpu_idle

The mainline kernel doesn't have this problem. Commit "(23588c3) x86,
amd: Add support for CPUID topology extension of AMD CPUs" removed the
family check. But 2.6.32.y needs to be fixed.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>