Merge remote-tracking branch 'origin/fmc-adc-bufg' into proposed_master

Merge discussed and approved by T. Gingold, needed for new releases of WRTD
reference designs and FMC-ADC-100M.
Status Job ID Name Coverage
  Wrpc Compile
failed #14579
modelsim 10.0c
job_wrpc_compile

 
  Wrpc Syn
skipped #14583
vivado 2018.3
job_wrpc_pxie_fmc
skipped #14580
ise
job_wrpc_spec
skipped #14581
ise
job_wrpc_svec
skipped #14582
16.0 quartus
job_wrpc_vfchd
 
  Wrpc Sim
skipped #14584
modelsim 10.0c
job_wrpc_sim