fix going back to crust after sms or missed call

RTC loops was storing the good wake up reason but not the classic crust.

We fix it to notify the modemmonitor with the reason of the wake. This
should solve the issue and put the phone back to crust after sms.

scripts/core/sxmo_screenlock.sh

@@ -145,15 +145,10 @@ elif [ "$1" = "crust" ] ; then
 	updateLed
 	xset dpms force on
 
-	# all we know is it's not the rtc. Maybe modem?
-	# TODO: Check mmcli or something or sxmo's notifs when
-	# https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/356
-	# https://gitlab.com/postmarketOS/pmaports/-/merge_requests/2066
-	# fixed
-	# TODO: Document UNSUSPENDREASONFILE
-	echo "nonrtc" > "$UNSUSPENDREASONFILE"
-
-	if [ "$(whichWake)" = "button" ] && [ -x "$XDG_CONFIG_HOME/sxmo/hooks/postwake" ]; then
+	UNSUSPENDREASON=$(whichWake)
+	echo "$UNSUSPENDREASON" > "$UNSUSPENDREASONFILE"
+
+	if [ "$UNSUSPENDREASON" = "button" ] && [ -x "$XDG_CONFIG_HOME/sxmo/hooks/postwake" ]; then
 		"$XDG_CONFIG_HOME/sxmo/hooks/postwake"
 	fi