MAINTAINERS: add new TTM maintainers

Roger unfortunately doesn't work for AMD any longer. So add Rui and
Jerry as co-maintainer as well.
Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

MAINTAINERS

@@ -4883,7 +4883,8 @@ F:	Documentation/gpu/xen-front.rst
 
 DRM TTM SUBSYSTEM
 M:	Christian Koenig <christian.koenig@amd.com>
-M:	Roger He <Hongbo.He@amd.com>
+M:	Huang Rui <ray.huang@amd.com>
+M:	Junwei Zhang <Jerry.Zhang@amd.com>
 T:	git git://people.freedesktop.org/~agd5f/linux
 S:	Maintained
 L:	dri-devel@lists.freedesktop.org