mtd: rawnand: cadence: Fix return type of CDMA send-and-wait helper

mtd: rawnand: cadence: Fix return type of CDMA send-and-wait helper

cadence_nand_cdma_send_and_wait() propagates negative errno values
from cadence_nand_cdma_send(), returns -ETIMEDOUT on failure and -EIO
when the CDMA engine reports a command failure.

However, it is declared as u32, causing error codes to wrap.
Change the return type to int to correctly propagate errors.

Fixes: ec4ba01e894d ("mtd: rawnand: Add new Cadence NAND driver to MTD subsystem")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>