Timestamp input
Added time tagging input (using the MINI_EXP2 input plus a input level converter).
Implemented circuit using DS90LV018A.
Modifications for firmware tracked here: https://gitlab.cern.ch/sbiereig/mcb2024_bladerf/
Required software currently here: https://gitlab.cern.ch/sbiereig/mcb2022_sdr_sw