MAINTAINERS: Add an entry for the vboxvideo driver

Add a MAINTAINERS entry for the vboxvideo driver, now that it has been
moved out of staging.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190311163522.22045-1-hdegoede@redhat.com

MAINTAINERS

@@ -4960,6 +4960,13 @@ S:	Odd Fixes
 F:	drivers/gpu/drm/udl/
 T:	git git://anongit.freedesktop.org/drm/drm-misc
 
+DRM DRIVER FOR VIRTUALBOX VIRTUAL GPU
+M:	Hans de Goede <hdegoede@redhat.com>
+L:	dri-devel@lists.freedesktop.org
+S:	Maintained
+F:	drivers/gpu/drm/vboxvideo/
+T:	git git://anongit.freedesktop.org/drm/drm-misc
+
 DRM DRIVER FOR VIRTUAL KERNEL MODESETTING (VKMS)
 M:	Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
 R:	Haneen Mohammed <hamohammed.sa@gmail.com>