Merge branch 'conn-port' into 'master'

Draft: output: add wlr_output.port

See merge request wlroots/wlroots!3979

include/wlr/types/wlr_output.h

@@ -192,6 +192,7 @@ struct wlr_output {
 	char *name;
 	char *description; // may be NULL
 	char *make, *model, *serial; // may be NULL
+	char *port; // may be NULL
 	int32_t phys_width, phys_height; // mm
 	const struct wlr_color_primaries *default_primaries; // may be NULL