[CountedPWM] Now driver handles the corner case of pulseFrequency equal to zero

When setting the pwm frequency to 0 Hz a division by zero was performed, leading to a crash of the system. Now we don't update the timers

src/shared/drivers/timer/CountedPWM.cpp

@@ -56,6 +56,10 @@ CountedPWM::~CountedPWM()
 void CountedPWM::setFrequency(unsigned int pulseFrequency)
 {
     this->pulseFrequency = pulseFrequency;
+
+    if (pulseFrequency == 0)
+        return;
+
     pulseTimer.setFrequency(pulseFrequency * dutyCycleResolution);
     pulseTimer.setAutoReloadRegister(
         TimerUtils::getFrequency(pulseTimer.getTimer()) / pulseFrequency);