dt-bindings: iommu: Add Qualcomm TBU

dt-bindings: iommu: Add Qualcomm TBU

The "apps_smmu" on the Qualcomm sdm845 platform is an implementation
of the SMMU-500, that consists of a single TCU (Translation Control
Unit) and multiple TBUs (Translation Buffer Units). These TBUs have
hardware debugging features that are specific and only present on
Qualcomm hardware. Represent them as independent DT nodes. List all
the resources that are needed to operate them (such as registers,
clocks, power domains and interconnects).

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Georgi Djakov <quic_c_gdjako@quicinc.com>
Link: https://lore.kernel.org/r/20240417133731.2055383-2-quic_c_gdjako@quicinc.com
Signed-off-by: Will Deacon <will@kernel.org>