x86: PAT proper tracking of set_memory_uc and friends

Big thinko in pat memtype tracking code. reserve_memtype should be called
with physical address and not virtual address.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>