Add a weston_pointer_axis_event

Use an event struct to pass axis events around. This helps dealing with the
upcoming axis discrete changes.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>
diff --git a/ivi-shell/hmi-controller.c b/ivi-shell/hmi-controller.c
index 77426bc..c21b9e0 100644
--- a/ivi-shell/hmi-controller.c
+++ b/ivi-shell/hmi-controller.c
@@ -1511,9 +1511,10 @@
 
 static void
 pointer_default_grab_axis(struct weston_pointer_grab *grab,
-			  uint32_t time, uint32_t axis, wl_fixed_t value)
+			  uint32_t time,
+			  struct weston_pointer_axis_event *event)
 {
-	weston_pointer_send_axis(grab->pointer, time, axis, value);
+	weston_pointer_send_axis(grab->pointer, time, event);
 }
 
 static void