mhi: cntrl: qcom: remove deprecated IOMMU APIs

IOMMU mapping APIs have been deprecated in favor of device
tree entries. Update MHI functions as required.

CRs-Fixed: 2398500
Change-Id: I0a7c0c9a83f1640430452ef07daf4f938b93b97d
Acked-by: Bhaumik Vasav Bhatt <bbhatt@qti.qualcomm.com>
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>