iommu: msm: Add base physical address to drvdata structure

Add the physical address value to the iommu drvdata structure. This
address is needed for debugging purposes when we get iommu page
faults and during iommu halt and tlb sync issues.

Change-Id: I2d4f36cdfe8a3da772839cb07cd186820f2e1f52
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>