V4L/DVB (3395): Hauppauge Grey Remote support

- For the Hauppauge PVR cards there are at least two different remotes, one
  completly black and one that is Grey and black, they keys differ in values
  eg Black remotes 'mute' has the same value as Grey remotes 'menu'.
- This enables the user to select which keymapping to use by using the
  hauppauge parm. Unlike to the black remote keys, all keys are
  mapped for the grey remote and the ATi usb remote mappings has been
  followed.

Signed-off-by: Ricardo Cerqueira <v4l@cerqueira.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>