compositor: add EGL_WL_bind_wayland_display definitions

This is a workaround for platforms, whose EGL headers miss the
definitions for EGL_WL_bind_wayland_display.

Signed-off-by: Pekka Paalanen <ppaalanen@gmail.com>
diff --git a/src/compositor.h b/src/compositor.h
index 045c8ac..a27a7a0 100644
--- a/src/compositor.h
+++ b/src/compositor.h
@@ -34,6 +34,8 @@
 
 #include "matrix.h"
 #include "../shared/config-parser.h"
+#include "weston-egl-ext.h"
+
 
 struct weston_transform {
 	struct weston_matrix matrix;