compositor-x11: Rename the output make to "weston-X11"

Previously all outputs in the X11 backend had the make "xwayland" which is
confusing.  Now they have something that makes a little more sense.
diff --git a/src/compositor-x11.c b/src/compositor-x11.c
index 3494e34..b602bc9 100644
--- a/src/compositor-x11.c
+++ b/src/compositor-x11.c
@@ -869,7 +869,7 @@
 	output->base.set_dpms = NULL;
 	output->base.switch_mode = NULL;
 	output->base.current_mode = &output->mode;
-	output->base.make = "xwayland";
+	output->base.make = "weston-X11";
 	output->base.model = "none";
 
 	if (configured_name)