egl: Add EGL_MESA_drm_image extension

Create EGLImages from DRM buffer handles.

src/egl/main/egldisplay.h

@@ -54,6 +54,7 @@ struct _egl_extensions
    EGLBoolean MESA_screen_surface;
    EGLBoolean MESA_copy_context;
    EGLBoolean MESA_drm_display;
+   EGLBoolean MESA_drm_image;
 
    EGLBoolean KHR_image_base;
    EGLBoolean KHR_image_pixmap;