iommu/io-pgtable: Rename iommu_gather_ops to iommu_flush_ops

In preparation for TLB flush gathering in the IOMMU API, rename the
iommu_gather_ops structure in io-pgtable to iommu_flush_ops, which
better describes its purpose and avoids the potential for confusion
between different levels of the API.

$ find linux/ -type f -name '*.[ch]' | xargs sed -i 's/gather_ops/flush_ops/g'

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

drivers/iommu/mtk_iommu.c

@@ -188,7 +188,7 @@ static void mtk_iommu_tlb_sync(void *cookie)
 	}
 }
 
-static const struct iommu_gather_ops mtk_iommu_gather_ops = {
+static const struct iommu_flush_ops mtk_iommu_flush_ops = {
 	.tlb_flush_all = mtk_iommu_tlb_flush_all,
 	.tlb_add_flush = mtk_iommu_tlb_add_flush_nosync,
 	.tlb_sync = mtk_iommu_tlb_sync,
@@ -267,7 +267,7 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom)
 		.pgsize_bitmap = mtk_iommu_ops.pgsize_bitmap,
 		.ias = 32,
 		.oas = 32,
-		.tlb = &mtk_iommu_gather_ops,
+		.tlb = &mtk_iommu_flush_ops,
 		.iommu_dev = data->dev,
 	};