Added "width" parameter which sets number of characters in ht16k33 display module

[maxim75]

ht16k33 IC supports up to 8 characters. I have made 6 character module and modified library to allow to config "width". Defaults to 4

display:
  - platform: ht16k33_alpha
    address: 0x70
    scroll: true
    scroll_speed: 250ms
    scroll_dwell: 2s
    scroll_delay: 4
    size: 6
    lambda: |-
      it.print("ABCDEFGH");