x86/topology: Set x86_max_cores to 1 for CONFIG_SMP=n

x86/topology: Set x86_max_cores to 1 for CONFIG_SMP=n

Josef reported that the uncore driver trips over with CONFIG_SMP=n because
x86_max_cores is 16 instead of 12.

The reason is, that for SMP=n the extended topology detection is a NOOP and
the cache leaf is used to determine the number of cores. That's wrong in two
aspects:

1) The cache leaf enumerates the maximum addressable number of cores in the
   package, which is obviously not correct

2) UP has no business with topology bits at all.

Make intel_num_cpu_cores() return 1 for CONFIG_SMP=n

Reported-by: Josef Bacik <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: kernel-team <[email protected]>
Cc: Kan Liang <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]