added ATtiny84 / 44 / 24 support, using pin defs from mellis 

Hi,
A quick pindefs addition to fastpin for WS2812/11 support.  Thanks for FastLED.

pindefs from mellis : https://github.com/damellis/attiny/blob/ide-1.5.x/attiny/avr/variants/tiny14/pins_arduino.h