firmware: qcom: scm: Add function to set the maximum IOMMU pool size

This is not necessary for basic functionality of the IOMMU, but
it's an optimization that tells to the TZ what's the maximum
mappable size for the secure IOMMUs, so that it can optimize
the data structures in the TZ itself.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
[Marijn: ported from 5.3 to the unified architecture in 5.11]
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211208083423.22037-3-marijn.suijten@somainline.org