iommu/dma: Fold _swiotlb helpers into callers

Fold the _swiotlb helper functions into the respective _page functions,
since recent fixes have moved all logic from the _page functions to the
_swiotlb functions.

Signed-off-by: David Stevens <stevensd@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210929023300.335969-5-stevensd@google.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>