Moves X4C_100, X4C_200, C1_100, and C1_200 from experimental to
available targets and makes the needed changes to allow them to build
successfully.
Adds support for "UC" FPGA variant. U indicates that QSFP0 is unused
and C indicates that QSFP1 is 100 GbE.
Adds experimental CG_200 variant.
Original-commit: cb9609c886b156e22ae9d879fffad8d060f2ca2d
Martin Braun