V4L/DVB (5964): Fixed remote control for dib0700 with new firmware

The new firmware returns the data of the REQUEST_POLL_RC request in
reversed order. The default is RC5, but it can be adjusted using a
module parameter.

Signed-off-by: Janne Grunau <janne-dvb@grunau.be>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>