msm: kgsl: Add support for GPUHTW System Cache usage

Activate and deactivate the slice for GPU pagetable walks
in the system cache upon GPU power collapse/restore.
Configure the SCID for the slice.
Also enable the SMMU domain attribute to allocate pagetable
memory with the right memory attributes for them to be
allocated into the system cache.

CRs-Fixed: 1081617
Change-Id: I16c174b413eaa4aa5c6a3514c9a18f8c990812da
Signed-off-by: Sushmita Susheelendra <ssusheel@codeaurora.org>