firmware: imx: scu: use dev_err_probe

This simplifies the code and silences -517 error messages. Also
the reason is listed in /sys/kernel/debug/devices_deferred.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>