debian: Setup leds via udev

This allows feedbackd to set periodic feedback and makes usable
LED devices identifiable by feedbackd.

debian/feedbackd.install

+debian/modules-load.d etc/
 /usr/bin/
 /usr/libexec/
 /usr/share/dbus-1/

debian/feedbackd.udev

@@ -6,4 +6,7 @@ ACTION=="remove", GOTO="feedbackd_end"
 
 SUBSYSTEM=="input", KERNEL=="event*", ENV{ID_INPUT}=="1", ENV{ID_PATH}=="platform-vibrator", TAG+="uaccess", ENV{FEEDBACKD_TYPE}="vibra"
 
+# Front leds of the Librem5
+SUBSYSTEM=="leds", DEVPATH=="*/phone:*:front", ENV{FEEDBACKD_TYPE}="led", RUN+="/usr/libexec/fbd-ledctrl -p %S%p -t pattern -G video"
+
 LABEL="feedbackd_end"

debian/modules-load.d/feedbackd.conf

+ledtrig-pattern