iommu/io-pgtable: Remove unused ->tlb_sync() callback

The ->tlb_sync() callback is no longer used, so it can be removed.

Signed-off-by: Will Deacon <will@kernel.org>

drivers/gpu/drm/panfrost/panfrost_mmu.c

@@ -269,7 +269,6 @@ static const struct iommu_flush_ops mmu_tlb_ops = {
 	.tlb_flush_all	= mmu_tlb_inv_context_s1,
 	.tlb_flush_walk = mmu_tlb_flush_walk,
 	.tlb_flush_leaf = mmu_tlb_flush_leaf,
-	.tlb_sync	= mmu_tlb_sync_context,
 };
 
 static const char *access_type_name(struct panfrost_device *pfdev,