Fix rotation while simplifying id detection.

We hardcode the default pinephone screen input id as we now can override
it by device.

scripts/core/sxmo_rotate.sh

@@ -5,9 +5,7 @@
 . "$(dirname "$0")/sxmo_common.sh"
 
 applyptrmatrix() {
-	TOUCH_POINTER_ID="${TOUCH_POINTER_ID:-
-		(xinput | grep -iE 'touchscreen.+pointer' | grep -oE 'id=[0-9]+' | cut -d= -f2)
-	}"
+	TOUCH_POINTER_ID="${TOUCH_POINTER_ID:-8}"
 	xinput set-prop "$TOUCH_POINTER_ID" --type=float --type=float "Coordinate Transformation Matrix" "$@"
 }