msm: kgsl: Add support for iommu V2 programming for A4xx

Add GPU self programming support for page table updates and
TLB flushes for IOMMU-v2 in A4xx. Also use VBIF recoverable HALT
feature to prevent the GPU from accessing the IOMMU while updates
are being done via dedicated AHB path. Identify GPU type in adreno_probe().
This is required to set SMMU AHB base for A405 to 0x48000.
Use CP_WIDE_REG_WRITE PM4 packet for IOMMU programming.
This is required to overcome limitation of type0 packet which allows
max register address 0x7FFF.

Change-Id: I58822204297ef69f15e30b25ab0dda72def43712
Signed-off-by: Ananta Kishore K <akollipa@codeaurora.org>