dmaengine: dw-axi-dmac: Increase polling time to DMA transmission completion status

dmaengine: dw-axi-dmac: Increase polling time to DMA transmission completion status

The bit DMAC_CHEN[0] is automatically cleared by hardware to disable the
channel after the last AMBA transfer of the DMA transfer to the
destination has completed. Software can therefore poll this bit to
determine when this channel is free for a new DMA transfer.
This time requires at least 40 milliseconds on JH7110 SoC, otherwise an
error message 'failed to stop' will be reported.

Signed-off-by: Walker Chen <walker.chen@starfivetech.com>
Link: https://lore.kernel.org/r/20230322094820.24738-4-walker.chen@starfivetech.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>