dmaengine: ti: edma: handle irq_of_parse_and_map() errors

dmaengine: ti: edma: handle irq_of_parse_and_map() errors

Zero is not a valid IRQ for in-kernel code and the irq_of_parse_and_map()
function returns zero on error.  So this check for valid IRQs should only
accept values > 0.

Fixes: 2b6b3b742019 ("ARM/dmaengine: edma: Merge the two drivers under drivers/dma/")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/f15cb6a7-8449-4f79-98b6-34072f04edbc@moroto.mountain
Signed-off-by: Vinod Koul <vkoul@kernel.org>