[media] rc/imon: fix ffdc device detection oops

There's a nasty bug that slipped in when the rc device interface was
altered, only affecting the older 0xffdc imon devices. We were trying
to access ictx->rdev->allowed_protos before ictx->rdev had been set.

There's also an issue with call ordering that meant the correct
keymap wasn't getting loaded for MCE IR type 0xffdc devices.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>