[media] Documentation: devicetree: add the RC map name of the geekbox remote

Keep the list up to date with include/media/rc-map.h

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

Documentation/devicetree/bindings/media/rc.txt

@@ -46,6 +46,7 @@ The following properties are common to the infrared remote controllers:
   * "rc-flyvideo"
   * "rc-fusionhdtv-mce"
   * "rc-gadmei-rm008z"
+  * "rc-geekbox"
   * "rc-genius-tvgo-a11mce"
   * "rc-gotview7135"
   * "rc-hauppauge"