dma: tegra: register as an OF DMA controller
dma: tegra: register as an OF DMA controller

Call of_dma_controller_register() so that DMA clients can look up the
Tegra DMA controller using standard APIs. This requires the of_xlate()
function to save off the DMA slave ID, and for tegra_dma_slave_config()
not to over-write this information; once DMA client drivers are converted
to dma_request_slave_channel() and DT-based lookups, they won't set this
field of struct dma_slave_config anymore.

Signed-off-by: Stephen Warren <5ef2a23ba3aff51d1cfc8c113c1ec34b608b3b13@nvidia.com>
Acked-by: Arnd Bergmann <f2c659f01951776204a6c5b902787d9019fbeebd@arndb.de>
Reviewed-by: Thierry Reding <3055038c414aef68bf32c33b8118623e7554e0f2@nvidia.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs