Extend multimedia keys

Extends the Qt keycodes with four missing keys, common on remote controls:
Guide, Info, Settings and Exit.

Change-Id: I6789f13dbb662da4261a3c947757644e12306dd9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: BogDan Vatra <bogdan@kde.org>