Arm SMMU updates for 5.15
- SMMUv3
* Minor optimisation to avoid zeroing struct members on CMD submission
* Increased use of batched commands to reduce submission latency
* Refactoring in preparation for ECMDQ support
- SMMUv2
* Fix races when probing devices with identical StreamIDs
* Optimise walk cache flushing for Qualcomm implementations
* Allow deep sleep states for some Qualcomm SoCs with shared clocks