iommu/arm-smmu-v3: Start a new batch if new command is not supported

iommu/arm-smmu-v3: Start a new batch if new command is not supported

The VCMDQ in the tegra241-cmdqv driver has a guest mode that supports only
a few invalidation commands. A batch is initialized with a cmdq, so it has
to confirm whether a new command is supported or not.

Add a supports_cmd function pointer to the cmdq structure, where the vcmdq
driver should hook a command scan function. Add an inline helper too so it
can be used by both sides.

If a new command is not supported, simply issue the existing batch and re-
init it as a new batch.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/aafb24b881504f18c5d0c7c15f2134e40ad2c486.1724970714.git.nicolinc@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>