Key mappings for more remote-control keys

We are missing a few key mappings to have support for remote control
keys supported by Android and DirectFB.

This patch adds the four color keys Red/Green/Yellow/Blue and ChannelUp
and ChannelDown.

Change-Id: I4d859c28e0d61c5362f1212ba1e577a47de86ec1
Reviewed-by: BogDan Vatra <bogdan@kde.org>
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>