msm: kgsl: Add support for IOMMU-v2

Add GPU self programming support for page table updates and
TLB flushes for IOMMU-v2. Also use VBIF recoverable HALT
feature to prevent the GPU from accessing the IOMMU while updates
are being done via dedicated AHB path.

Change-Id: If8c7f27f5437ff1c0be46a72f898eaa290e56024
Signed-off-by: Rajesh Kemisetti <rajeshk@codeaurora.org>
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>