Remove trend
Simplify trend away.
passed Non-regression STC:
https://tests.stockfishchess.org/tests/view/63642a63a90afcecbd1cb887
LLR: 2.95 (-2.94,2.94) <-1.75,0.25>
Total: 130000 W: 34683 L: 34567 D: 60750
Ptnml(0-2): 455, 14424, 35135, 14522, 464
passed Non-regression LTC:
https://tests.stockfishchess.org/tests/view/636566fda90afcecbd1cded9
LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 81592 W: 21938 L: 21787 D: 37867
Ptnml(0-2): 42, 8035, 24490, 8188, 41
closes https://github.com/official-stockfish/Stockfish/pull/4222
Bench: 4239512