MAINTAINERS: Move fsl-dcu driver to drm-misc tree

The driver is mostly in maintenance mode. Using drm-misc is a
good fit and should make maintenance a bit easier.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20180926125034.4095-1-stefan@agner.ch

MAINTAINERS

@@ -4824,6 +4824,7 @@ F:	drivers/gpu/drm/fsl-dcu/
 F:	Documentation/devicetree/bindings/display/fsl,dcu.txt
 F:	Documentation/devicetree/bindings/display/fsl,tcon.txt
 F:	Documentation/devicetree/bindings/display/panel/nec,nl4827hc19-05b.txt
+T:	git git://anongit.freedesktop.org/drm/drm-misc
 
 DRM DRIVERS FOR FREESCALE IMX
 M:	Philipp Zabel <p.zabel@pengutronix.de>