RegFGC3-WR-BTrain

WR-BTrain receiver eference design for RegFGC3 FMC carrier. This design instantiates BTrain over FMC interface. The FMC should be the CUTE-WR-DP FMC with cute_ref_design (v1.2) from https://gitlab.cern.ch/BTrain-TEAM/Btrain-over-WhiteRabbit