ModemManager: add service options

Signed-off-by: Florian Eckert <fe@dev.tdt.de>

net/modemmanager/files/modemmanager.init

@@ -4,6 +4,8 @@
 USE_PROCD=1
 START=70
 
+LOG_LEVEL="INFO"
+
 stop_service() {
 	# Load common utils
 	. /usr/share/ModemManager/modemmanager.common
@@ -28,6 +30,8 @@ start_service() {
 	. /usr/share/ModemManager/modemmanager.common
 	procd_open_instance
 	procd_set_param command /usr/sbin/ModemManager-wrapper
+	procd_append_param command --log-level="$LOG_LEVEL"
+	[ "$LOG_LEVEL" = "DEBUG" ] && procd_append_param command --debug
 	procd_set_param respawn "${respawn_threshold:-3600}" "${respawn_timeout:-5}" "${respawn_retry:-5}"
 	procd_set_param pidfile "${MODEMMANAGER_PID_FILE}"
 	procd_close_instance