Fix LP SB_LUT4 timing
Fix LP SB_LUT4 timing

SymbiFlow/yosys,SymbiFlow/yosys,YosysHQ/yosys,YosysHQ/yosys,cliffordwolf/yosys,cliffordwolf/yosys,YosysHQ/yosys,cliffordwolf/yosys,cliffordwolf/yosys,cliffordwolf/yosys,SymbiFlow/yosys,antmicro/yosys,antmicro/yosys,YosysHQ/yosys,cliffordwolf/yosys,SymbiFlow/yosys,SymbiFlow/yosys,antmicro/yosys,antmicro/yosys,antmicro/yosys,antmicro/yosys,antmicro/yosys,cliffordwolf/yosys,SymbiFlow/yosys,antmicro/yosys,cliffordwolf/yosys,cliffordwolf/yosys,YosysHQ/yosys,YosysHQ/yosys,YosysHQ/yosys,YosysHQ/yosys,SymbiFlow/yosys,SymbiFlow/yosys