MAINTAINERS: Add entry for Himax HX8394 panel controller driver

Add myself as maintainer for the driver and devicetree bindings schema.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230102230733.3506624-4-javierm@redhat.com

MAINTAINERS

@@ -6480,6 +6480,14 @@ S:	Maintained
 T:	git git://anongit.freedesktop.org/drm/drm-misc
 F:	drivers/gpu/drm/tiny/gm12u320.c
 
+DRM DRIVER FOR HIMAX HX8394 MIPI-DSI LCD panels
+M:	Ondrej Jirman <megi@xff.cz>
+M:	Javier Martinez Canillas <javierm@redhat.com>
+S:	Maintained
+T:	git git://anongit.freedesktop.org/drm/drm-misc
+F:	Documentation/devicetree/bindings/display/panel/himax,hx8394.yaml
+F:	drivers/gpu/drm/panel/panel-himax-hx8394.c
+
 DRM DRIVER FOR HX8357D PANELS
 M:	Emma Anholt <emma@anholt.net>
 S:	Maintained