Review and merge fmc-adc-bufg branch in proposed_master of WRPC
ADC ref designs require the fmc-adc-bufg branch (for commit https://ohwr.org/project/wr-cores/commit/3884a65545907de3a0d41d549a4be9e6cccb4916).
This need to be reviewed and merged in proposed_master of WRPC.
We must NOT rebase this and delete the branch, as it is already pointed to by FMC-ADC release v6.0.3.
Once done, we need to test everything again with the latest WRPC commit.