dmaengine: PL08x: fix missed dma_transfer_direction fixup

db8196df

 (dmaengine: move drivers to dma_transfer_direction) missed
fixing up the "DMA_NONE" case.

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