rootston.ini: Map seat to DSI-1 instead of HDMI
This makes rotation work and it's far more likely to be used on the LCD atm. This needs a proper fix in the compositor to be better at input mapping (https://source.puri.sm/Librem5/wlroots/issues/23).
Signed-off-by: Guido Günther guido.gunther@puri.sm