iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync()

To allow IOMMU drivers to batch up TLB flushing operations and postpone
them until ->iotlb_sync() is called, extend the prototypes for the
->unmap() and ->iotlb_sync() IOMMU ops callbacks to take a pointer to
the current iommu_iotlb_gather structure.

All affected IOMMU drivers are updated, but there should be no
functional change since the extra parameter is ignored for now.

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

drivers/iommu/rockchip-iommu.c

@@ -794,7 +794,7 @@ static int rk_iommu_map(struct iommu_domain *domain, unsigned long _iova,
 }
 
 static size_t rk_iommu_unmap(struct iommu_domain *domain, unsigned long _iova,
-			     size_t size)
+			     size_t size, struct iommu_iotlb_gather *gather)
 {
 	struct rk_iommu_domain *rk_domain = to_rk_domain(domain);
 	unsigned long flags;