dmaengine: fsl-edma: add safety check for 'srcid'

Ensure that 'srcid' is a non-zero value to avoid dtb passing invalid
'srcid' to the driver.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20240323-8ulp_edma-v3-2-c0e981027c05@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>