Before this change, only the channel 0 ATR state was sent to the
db_control module. For TwinRX, this had the disadvantage that when only
Channel 1 was used, the FP- and LED-GPIOs could not track the radio's
ATR state (e.g., no LED would light up in this case).
Note that unlike UHD 3, there is only one db_control module per slot.
There are therefore no options to map GPIOs to track the ATR state of an
individual channel.
Original-commit: f23ab72129041777bcd3357a1f4e37b29e62dd86
Martin Braun
537684dc86