firmware: qcom_scm: add two scm calls for iommu secure page table

Those two new SCM calls are needed from qcom-iommu driver in order
to initialize secure iommu page table.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Andy Gross <andy.gross@linaro.org>