input: use doubles in the interfaces to notify of input events

This patch is a further step in the wl_fixed_t internal sanitization.
It changes the notify_* functions to take doubles instead of wl_fixed_t
but does not change how these are stored in the various input structs
yet, except for weston_pointer_axis_event.
However this already allows to remove all wl_fixed_t usage in places
like the libinput or the x11 backend.

Reviewed-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/src/screen-share.c b/src/screen-share.c
index 9b5154b..196173e 100644
--- a/src/screen-share.c
+++ b/src/screen-share.c
@@ -142,7 +142,8 @@
 	/* No transformation of input position is required here because we are
 	 * always receiving the input in the same coordinates as the output. */
 
-	notify_motion_absolute(&seat->base, time, x, y);
+	notify_motion_absolute(&seat->base, time,
+			       wl_fixed_to_double(x), wl_fixed_to_double(y));
 	notify_pointer_frame(&seat->base);
 }
 
@@ -165,7 +166,7 @@
 	struct weston_pointer_axis_event weston_event;
 
 	weston_event.axis = axis;
-	weston_event.value = value;
+	weston_event.value = wl_fixed_to_double(value);
 	weston_event.has_discrete = false;
 
 	notify_axis(&seat->base, time, &weston_event);