egl/dri2: Dispatch eglSwapBuffers  by display, not driver

Add dri2_egl_display_vtbl::swap_buffers, set it for each platform, and
let egl_dri2 dispatch eglSwapBuffers to that.

This prepares for the EGL platform extensions.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
index e1a8e1e..0b56c12 100644
--- a/src/egl/drivers/dri2/egl_dri2.c
+++ b/src/egl/drivers/dri2/egl_dri2.c
@@ -1022,6 +1022,13 @@
 }
 
 static EGLBoolean
+dri2_swap_buffers(_EGLDriver *drv, _EGLDisplay *dpy, _EGLSurface *surf)
+{
+   struct dri2_egl_display *dri2_dpy = dri2_egl_display(dpy);
+   return dri2_dpy->vtbl->swap_buffers(drv, dpy, surf);
+}
+
+static EGLBoolean
 dri2_wait_client(_EGLDriver *drv, _EGLDisplay *disp, _EGLContext *ctx)
 {
    struct dri2_egl_display *dri2_dpy = dri2_egl_display(disp);
@@ -2045,6 +2052,7 @@
    dri2_drv->base.API.BindTexImage = dri2_bind_tex_image;
    dri2_drv->base.API.ReleaseTexImage = dri2_release_tex_image;
    dri2_drv->base.API.SwapInterval = dri2_swap_interval;
+   dri2_drv->base.API.SwapBuffers = dri2_swap_buffers;
    dri2_drv->base.API.CreateImageKHR = dri2_create_image_khr;
    dri2_drv->base.API.DestroyImageKHR = dri2_destroy_image_khr;
 #ifdef HAVE_DRM_PLATFORM