dmaengine: virt-dma: vchan_find_desc()

Add a function to find a descriptor within the depths of the
virtualized DMA channel support.  Needed for tx_status functionality.

Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2 files changed