Follow-up the PR #3643(Temperature singleton)
・Change from fanSpeedSoftPwm[0] to thermalManager.fanSpeedSoftPwm[0] in planner.cpp
It fix compilation error when FAN_SOFT_PWM is enabled.
・Remove declaration of setExtruderAutoFanState() in temperature.h
Because that function was abolished.
・Change from babystepsTodo to thermalManager.babystepsTodo in ultralcd.cpp
It fix compilation errors when BABYSTEPPING is enabled.