vga_switcheroo: add reprobe hook for fbcon to recheck connected outputs.

This adds a hook after the mux is switched for the driver to reprobe
the connected outputs.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/radeon_device.c

@@ -779,6 +779,7 @@ int radeon_device_init(struct radeon_device *rdev,
 	vga_client_register(rdev->pdev, rdev, NULL, radeon_vga_set_decode);
 	vga_switcheroo_register_client(rdev->pdev,
 				       radeon_switcheroo_set_state,
+				       NULL,
 				       radeon_switcheroo_can_switch);
 
 	r = radeon_init(rdev);