Allow waveforms to be specified in clock cycles by earlephilhower · Pull Request #7211 · esp8266/Arduino

@earlephilhower

Allow the PWM to specify sub-microsecond waveform edges, as have been
proposed by @dok-net and me.  No other changes intended.

This will increase the linearity at 30 and 40 kHZ PWM rates, but leave
most other things unaffected.

devyte

devyte

@earlephilhower

@devyte