Revert "ARM: dts: msm: Disable iommu test clients"

This reverts commit eac426cb.
Since the smmu clock issue is now solved. Re-enable the
test clients.

Change-Id: Ic66c5ab869052b1c4ae0518f82751f08c3d0a7ea
Signed-off-by: Sudarshan Rajagopalan <sudaraja@codeaurora.org>