soc: tegra: fuse: Use dma_request_channel instead of __dma_request_channel()

The __dma_request_channel() prototype has been changed to help to do
device node validation, thus we can use dma_request_channel() instead
of __dma_request_channel() to keep kernel bisectable.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>