kinetis:Bug fix PWM led update
kinetis:Bug fix PWM led update

  The code was forcing the CV reload, but not resettting the count
  this would cause short and long blinks during breathing.

  this change allows the CV to update at 50Hz (20 ms) asynchronously.
  So the LED update rate of 40Hz (25) will take effect on the next
  FTM counter change, end of the prescaler counting, after CnV register
  was written.update.
                   a   b   c   d
  LED PWM   ___-___-___-___-___-___-___-___-___-___
  LED Data  ____-____-____-____-____-____-____-____-
                 a    b    c    d

mje-nz/PX4-Firmware,PX4/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,acfloria/Firmware,dagar/Firmware,PX4/Firmware,krbeverx/Firmware,Aerotenna/Firmware,acfloria/Firmware,acfloria/Firmware,Aerotenna/Firmware,krbeverx/Firmware,dagar/Firmware,Aerotenna/Firmware,krbeverx/Firmware,acfloria/Firmware,dagar/Firmware,krbeverx/Firmware,dagar/Firmware,acfloria/Firmware,Aerotenna/Firmware,PX4/Firmware,krbeverx/Firmware,krbeverx/Firmware,mje-nz/PX4-Firmware,Aerotenna/Firmware,dagar/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,mje-nz/PX4-Firmware,acfloria/Firmware,dagar/Firmware,krbeverx/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,dagar/Firmware,PX4/Firmware,acfloria/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,PX4/Firmware