arm: select the dma-noncoherent symbols for all swiotlb builds

We need to provide the arch hooks for non-coherent dma-direct
and swiotlb for all swiotlb builds, not just when LPAS is enabled.
Without that the Xen build that selects SWIOTLB indirectly through
SWIOTLB_XEN fails to build.

Fixes: ad3c7b18

 ("arm: use swiotlb for bounce buffering on LPAE configs")
Reported-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Stefan Wahren <wahrenst@gmx.net>