libweston: Use struct timespec for axis events

Change code related to axis events to use struct timespec to represent
time.

This commit is part of a larger effort to transition the Weston codebase
to struct timespec.

Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

ivi-shell/hmi-controller.c

@@ -1461,7 +1461,7 @@ pointer_noop_grab_focus(struct weston_pointer_grab *grab)
 
 static void
 pointer_default_grab_axis(struct weston_pointer_grab *grab,
-			  uint32_t time,
+			  const struct timespec *time,
 			  struct weston_pointer_axis_event *event)
 {
 	weston_pointer_send_axis(grab->pointer, time, event);