iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->tlb_add_page()

With all the pieces in place, we can finally propagate the
iommu_iotlb_gather structure from the call to unmap() down to the IOMMU
drivers' implementation of ->tlb_add_page(). Currently everybody ignores
it, but the machinery is now there to defer invalidation.

Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index f668995..5598d0f 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -574,7 +574,8 @@ static void arm_smmu_tlb_inv_leaf(unsigned long iova, size_t size,
 	ops->tlb_sync(cookie);
 }
 
-static void arm_smmu_tlb_add_page(unsigned long iova, size_t granule,
+static void arm_smmu_tlb_add_page(struct iommu_iotlb_gather *gather,
+				  unsigned long iova, size_t granule,
 				  void *cookie)
 {
 	struct arm_smmu_domain *smmu_domain = cookie;