dmaengine: fsl-edma: refactor chan_name setup and safety

Relocated the setup of chan_name from setup_irq() to fsl_chan init. This
change anticipates its future use in various locations.

For increased safety, sprintf has been replaced with snprintf. In addition,
The size of the fsl_chan->name[] array was expanded from 16 to 32.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20230821161617.2142561-10-Frank.Li@nxp.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>