weston: add video buffer display time event [1/2]

PD#SWPL-175341

Problem:
need video frame display interval info.

Solution:
add video buffer display time event.

Verify:
ah212

Change-Id: I797de5bdad8484498fb4a99562a7cde775d8b50e
Signed-off-by: limin.tian <limin.tian@amlogic.com>
diff --git a/libweston/compositor.c b/libweston/compositor.c
index eb7a5f6..888af4a 100644
--- a/libweston/compositor.c
+++ b/libweston/compositor.c
@@ -3489,6 +3489,9 @@
 		buffer->surface = surface;
 		buffer->attach = buffer->attach+1;
 		buffer->ec = surface->compositor;
+		if (surface) {
+			buffer->enable_display_time = surface->enable_display_time;
+		}
 	}
 
 	/* Attach, attach, without commit in between does not send
@@ -4102,7 +4105,8 @@
 	surface_destroy_callback,
 	surface_enable_ll_mode,
 	surface_set_invisible,
-	surface_set_plane_mute
+	surface_set_plane_mute,
+	surface_enable_display_time_callback
 };
 
 static int