Basically this is a Jewish numerology. Every Hebrew letter is assigned a number. This Gematria calculator computes a value for it AND it gives you other phrases that also match that number.

Play around with the calculator, you can try different words, they don't produce "DO IT Q". Luck is a special word that produces it.

If you go back through the history of Q, they have used the phrase "DO IT Q" before.

Basically this is not a random coincidence. They knew that "Luck" could be converted to "Do IT Q" and Trump just referenced it!