The Knicks and Precious Achiuwa have reached a one-year agreement worth $6 million, Achuiwa’s agent, Raymond Brothers, told SNY on Tuesday. Achiuwa agreed to waive his no-trade clause as part of the agreement, per SNY sources. Achiuwa, 24, averaged 7.6 points on 52.5 percent from the field and 7.2 rebounds per game across 49 games (18 starts) for the Knicks …