x86: apic - generic_processor_info

- use physid_set instead of phys_cpu and physids_or
- set phys_cpu_present_map bit AFTER check for allowed
  number of processors
- add checking for APIC valid version in 64bit mode
  (mostly not needed but added for merging purpose)
- add apic_version definition for 64bit mode which
  is used now

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>