defconfig: msm-copper: Enable MSM IOMMU support

SMMU v2 support is required by the multimedia cores to access
memory in virtually contiguous fashion with SMMU taking care of
performing the address translation to discontiguous physical
memory regions.

Change-Id: I154b4c5c4b06094d60bf6e52f45e7e17d1fe328f
Signed-off-by: Sathish Ambley <sambley@codeaurora.org>