imx-uuc: fix start-stop-daemon stop failure

imx-uuc: fix start-stop-daemon stop failure

The daemon service script associated with imx-uuc failed to stop the daemon
since the PID of the process wasn't stored at start time.

Adding -m option allowed to create the uuc.pid file as expected.

Signed-off-by: Alexandre Esse <alexandre.esse.dev@gmail.com>
Reviewed-by: Gary Bisson <gary.bisson@boundarydevices.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
(cherry picked from commit 41e86cd5cad853d7778231be8ce7c6fdb87e3da4)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>