iommu/arm-smmu-v3: Add an ops indirection to the STE code

Prepare to put the CD code into the same mechanism. Add an ops indirection
around all the STE specific code and make the worker functions independent
of the entry content being processed.

get_used and sync ops are provided to hook the correct code.
Signed-off-by: Michael Shavit <mshavit@google.com>
Reviewed-by: Michael Shavit <mshavit@google.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v9-5040dc602008+177d7-smmuv3_newapi_p2_jgg@nvidia.comSigned-off-by: Will Deacon <will@kernel.org>