mtrr: fix size_or_mask and size_and_mask

This fixes two bugs in /proc/mtrr interface:
o If physical address size crosses the 44 bit boundary
  size_or_mask is evaluated wrong.
o size_and_mask limits width of physical base
  address for an MTRR to be less than 44 bits.

TBD: later patch had one more change, but I think that was bogus.
TBD: need to double check
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: NAndi Kleen <ak@suse.de>