iommu/arm-smmu-v3: Directly encode CMDQ_OP_SYNC

iommu/arm-smmu-v3: Directly encode CMDQ_OP_SYNC

Change the flow so the caller controls the CS field and remove the
weird u64p_replace_bits() thing to override it.

Reviewed-by: Pranjal Shrivastava <praan@google.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Tested-by: Pranjal Shrivastava <praan@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Samiullah Khawaja <skhawaja@google.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>