esp32-s2: Don't set PWMOut frequency to 0
esp32-s2: Don't set PWMOut frequency to 0

FeatherS2 crashes if you set the PWMOut frequency to 0.
This change will raise `ValueError: Invalid PWM frequency` if the requested frequency is 0.
(Lifted from the atmel-samd port)
adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython