Constraints from LVDS blocks and logic

It's probably talking about MCs for the Classic Timing Analyzer(which behind the scenes would add a hold multicycle). For the most part, a setup mc of 2 in classic would be done by a setup MC of 2 and hold MC of 1 in TimeQuest. Or more exactly, a setup of N in Classic is a setup MC of N and a hold MC of N-1 in TimeQuest.

(Although if you're phase-shifting your clock, that may not be accurate, since Classic TAN did a thing called normalization. For whatever MCs you add, I would explicitly do a report_timing -setup and -hold on those paths and make sure the setup and hold requirement is what you expect.)