[media] imon: auto-config ffdc 7e device

Another device with the 0xffdc device id, this one with 0x7e in the
config byte. Its an iMON VFD + RC6 IR, in a CoolerMaster 260 case.

Reported-by: Filip Streibl <filip@streibl.cz>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>