[media] dvb_usb_v2: make remote controller optional

Make it possible to compile dvb_usb_v2 driver without the remote
controller (RC-core).

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --cc drivers/media/usb/dvb-usb-v2/Kconfig
Simple merge

diff --cc drivers/media/usb/dvb-usb-v2/dvb_usb.h
Simple merge

diff --cc drivers/media/usb/dvb-usb-v2/dvb_usb_core.c
Simple merge