add EGL_TEXTURE_EXTERNAL_WL to WL_bind_wayland_display spec

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>

include/EGL/eglmesaext.h

@@ -52,6 +52,7 @@ extern "C" {
 #define EGL_TEXTURE_Y_U_V_WL            0x31D7
 #define EGL_TEXTURE_Y_UV_WL             0x31D8
 #define EGL_TEXTURE_Y_XUXV_WL           0x31D9
+#define EGL_TEXTURE_EXTERNAL_WL         0x31DA
 
 struct wl_display;
 struct wl_resource;