ntb: Use consistent DMA attributes when freeing DMA mappings

ntb: Use consistent DMA attributes when freeing DMA mappings

The counterpart of dma_alloc_attrs() is dma_free_attrs(), which must
receive the same DMA attributes used during allocation. The code
previously used dma_free_coherent(), which does not accept or apply any
DMA attributes.

Fixes: 061a785a114f ("ntb: Force physically contiguous allocation of rx ring buffers")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260501-dma-attrs-debug-v2-2-8dbac75cd501@nvidia.com