msm: ocmem: Add macro and region size information to ocmem region

Some targets support half sized macros in the last region. Previously,
for these regions, only half the macros were turned on, and the clients
could not access memory. Read the hardware register to check if the
target supports half sized macros and update the calculation to switch
memory power states.

Change-Id: Idb6e6b8c11b42d3e0a72fa27bd8c63e48282af97
Signed-off-by: Neeti Desai <neetid@codeaurora.org>