slimbus: slim-msm-ngd: Add 64 bit iommu mask support

Added 64 bit mask support in slimbus driver for iommu mapping.

Change-Id: I7d4a6be851346c372e0745f6e1bcdb9d71111886
Signed-off-by: Subramanian Ananthanarayanan <skananth@codeaurora.org>