Added support for GSM in the modemmgr plugin.

test/mm.sh

 #!/bin/dash
 
 IDBUS=org.freedesktop.DBus
 DBUS=/org/freedesktop/DBus
 IDBUS_PROPERTIES=$IDBUS.Properties
 IMM=org.freedesktop.ModemManager
 IMODEM=$IMM.Modem
 IMODEM_SIMPLE=$IMODEM.Simple
 IMODEM_CDMA=$IMODEM.Cdma
 IMODEM_GSM=$IMODEM.Gsm
 IMODEM_GSM_CARD=$IMODEM_GSM.Card
 IMODEM_GSM_NETWORK=$IMODEM_GSM.Network
 IMODEM_GOBI=org.chromium.ModemManager.Modem.Gobi
-IMODEMS="$IMODEM $IMODEM_SIMPLE $IMODEM_CDMA $IMODEM_GSM $IMODEM_GOBI"
+IMODEMS="$IMODEM $IMODEM_CDMA $IMODEM_GSM_CARD $IMODEM_GSM_NETWORK $IMODEM_GOBI"
 
 MTYPE_GSM=1
 MTYPE_CDMA=2
 
 iface2rootobj () {
         echo "/$1" | sed -e 's!\.!/!g'
 }
 
 dbus () {
         local dest=$1
@@ skipping 22 matching lines @@
                         | awk '/[^[:space:]] [^[:space:]]/ {print $N}'
         done
 }
 
 modemprop () {
         local mm=$1
         local modem=$2
         local prop=$3
         modemprops $mm $modem | grep /$prop | awk '{print $2}'
 }