V4L/DVB (4880): budget-ci IR: decode rc5 device byte

V4L/DVB (4880): budget-ci IR: decode rc5 device byte

Decode the RC5 device byte as well as the command byte. Introduce a
parameter to set the device events to listen for. Default to try
to auto-detect the proper device code, otherwise, listen to any
device as the old code did.
Based on Darren Salt's dvb-ir patchset.

Signed-off-by: Darren Salt <linux@youmustbejoking.demon.co.uk>
Signed-off-by: David Hardeman <david@hardeman.nu>
Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>