msm: kgsl: LPAC is using incorrect pagetable

We are incorrectly using the default pagetable for LPAC when per-process
page tables are disabled. Create a separate pagetable for LPAC.

Change-Id: I93b9c764fe91260b8b27c9b2d847429d1595a839
Signed-off-by: Raghu Ananya Arabolu <rarabolu@codeaurora.org>