linux-imx

MLK-15330-1: dma: fsl-edma-v3: combine two cells into one

For dual fifo case, fsl-edma-v3 need add another cell. It's not friendly
for user and it's possible other cells maybe added to other use cases,
so combine two cells into one now, and for some special use cases such as
dual fifo property can directly be passed by one bit of cell3 rather than
another cell.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
(cherry picked from commit 3ecd1b3382e2c746728842fb2c084fbb030eb5de)