[media] rc/keymaps: add a keytable for the GeekBox remote control

The GeekBox ships with a 12 button remote control which seems to use the
NEC protocol. The button keycodes were captured with the "ir-keytable"
tool (ir-keytable -p $PROTOCOL -t; human_button_pusher).

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