V4L/DVB (9639): Make dib0700 remote control support work with firmware v1.20

The format for reading the IR controller changed in firmware 1.20.  It now
provides the events on bulk endpoint 1 instead of using a control request.

Support the new format, providing backward compatibility for users who might
be using older firmware.

Thanks to Patrick Boettcher <patrick.boettcher@desy.de> for providing the
required information on how the version 1.20 firmware works.

Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>