Wait a minute, maybe not!
There are lots of reasons dogs lick, and they are not necessarily to show affection. Dogs lick because they are nervous, to show dominance, or just because something, or someone, tastes good. None of these are reasons to encourage or condone your dog licking your baby. In addition, there are health hazards associated with your dog's baby-licking behavior. Dogs can carry bacteria, viruses, and parasites that are transmissible to humans through saliva and licking behavior. These are absolutely the last things you want your dog sharing with your baby.
You will need lots of treats to reinforce appropriate behavior. Invest some time observing and supervising your baby and your dog to catch unwanted licking behaviors. Dogs and babies should never be left together unsupervised, so practicing constant supervision to prevent licking and other unwanted behaviors is a necessary habit to establish. You will want to stop your dog licking, not just of the baby, but of everyone. All members of the household will have to be on board, including guests, in extinguishing licking behaviors.