Even though her teenage son was singled out by James Dolan for chanting “Sell the Knicks’’ Wednesday night, removed from his seat by security, detained for 15 minutes and had his student ID taken, the boy’s mother said she’s “all good’’ with the Knicks owner. “[Dolan] called me [Thursday],’’ the mother, who insisted on anonymity, told The Post. “We had a pleasant and respectful conversation. It’s all good.’’