msm: camera: smmu: Add support for non-contiguous mermory region

Add support to discard a memory region inside the full dma map
virtual address space region.

CRs-Fixed: 2580128
Change-Id: I76cc778f2437a01a4efabec836ce92c47d983d61
Signed-off-by: Pavan Kumar Chilamkurthi <pchilamk@codeaurora.org>