iommu/arm-smmu-v3: Remove the unused empty definition

iommu/arm-smmu-v3: Remove the unused empty definition

arm_smmu_sva_remove_dev_pasid() has been removed since commit d38c28dbefee
("iommu/arm-smmu-v3: Put the SVA mmu notifier in the smmu_domain"), remain
the empty definition untouched in header file, which is used when
CONFIG_ARM_SMMU_V3_SVA is not set. So, let's remove the unused definition.

Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240815111504.48810-1-zhangzekun11@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>