Put the display in the touchbar seat too

This should prevent most compositors that don't check the non_desktop
property from opening the display device. Removing the "master-of-seat"
tag is necessary to prevent the seat from being considered existent, in
which case the login manager might try to start a graphical session in
it.

Author: kekrby

etc/udev/rules.d/99-touchbar-seat.rules

@@ -1,2 +1,4 @@
+SUBSYSTEM=="drm", KERNEL=="card*", DRIVERS=="adp", TAG-="master-of-seat", ENV{ID_SEAT}="seat-touchbar"
+
 SUBSYSTEM=="input", ATTR{name}=="MacBookPro17,1 Touch Bar", ENV{ID_SEAT}="seat-touchbar"
 SUBSYSTEM=="input", ATTR{name}=="Mac14,7 Touch Bar", ENV{ID_SEAT}="seat-touchbar"