xen: extend xen_swiotlb_dma_ops with map_resource and unmap_resource

commit 3172a0ac6c468f79ae7679effb3f9d3310b1deb5 from
https://source.codeaurora.org/external/autobsps32/linux



dma_map_resource requires a map_resource callback to be non-NULL,
otherwise it returns a mapping error.
fsl-edma DMA driver uses dma_map_resource for 5.4, added from upstream
in commit:
	0fa89f97: dmaengine: fsl-edma: dma map slave device address

When using fsl-edma over Xen, dma_map_resource requires the map_resource
callback to be implemented in xen_swiotlb_dma_ops.

Add map_resource and unmap_resources for xen_swiotlb using direct
mapping similar to dma_direct_map_resource()

Issue: ALB-5458
Signed-off-by: Catalin Udma <catalin-dan.udma@nxp.com>
Signed-off-by: Andrei Cherechesu <andrei.cherechesu@nxp.com>
Signed-off-by: Zhantao Tang <zhantao.tang@windriver.com>