Split the ref_count field of the bottom level of the vtophys map tree to
a separate array so that the pfn_2mb field can be expanded to a full 64
bits again. This doesn't change behavior for the current use as a page
frame number; it is setup work for storing an arbitrary 64-bit pointer
value in the bottom level.
Change-Id: I0bc44df3edc9df4a479229d69c2f3884d43a340d
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
a9133b405a