msm: kgsl: Add support for pre-allocated GMU buffers

Add support for a list of static GMU buffers that
are allocated and mapped at init. These buffers
are not expected to change in size. They are not
really required to be allocated through MEM_ALLOC
HFI packets. The base addresses of a few of these
buffers are conveyed to the GMU by placing them
at predefined sections that live at the respective
addresses in the scatter file.

Change-Id: I58466f4d285724357d33e83733e847f6fadde08b
Signed-off-by: Carter Cooper <ccooper@codeaurora.org>