Marlin: Temperature soft-PWM cleanup

Marlin/temperature.cpp

     #if ENABLED(FAST_PWM_FAN)
       setPwmFrequency(FAN_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
     #endif
-    #if ENABLED(FAN_SOFT_PWM)
-      soft_pwm_fan[0] = fanSpeedSoftPwm[0] >> 1;
-    #endif
   #endif
 
   #if HAS_FAN1
     #if ENABLED(FAST_PWM_FAN)
       setPwmFrequency(FAN1_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
     #endif
-    #if ENABLED(FAN_SOFT_PWM)
-      soft_pwm_fan[1] = fanSpeedSoftPwm[1] >> 1;
-    #endif
   #endif
 
   #if HAS_FAN2
     #if ENABLED(FAST_PWM_FAN)
       setPwmFrequency(FAN2_PIN, 1); // No prescaling. Pwm frequency = F_CPU/256/8
     #endif
-    #if ENABLED(FAN_SOFT_PWM)
-      soft_pwm_fan[2] = fanSpeedSoftPwm[2] >> 1;
-    #endif
   #endif
 
   #if ENABLED(HEATER_0_USES_MAX6675)