ARM: dts: msm: add iommu device support for msm8937

Add the IOMMU device tree support which is required to
support multiple clients that uses SMMU for VA to PA
translations.

Change-Id: I567ba7d6711aaacf0af09cd9e62c101c2f952fbf
Signed-off-by: Qingqing Zhou <qqzhou@codeaurora.org>
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>