Adjust reset timing for new WS2812 chip

[jobevers]

The old chips required a 50 microsecond reset; the new ones require 300.

See https://blog.adafruit.com/2017/05/03/psa-the-ws2812b-rgb-led-has-been-revised-will-require-code-tweak/

[jobevers]

Note that I haven't actually tested this on a BBB; I expect that there are more changes required to get this to work...

Mostly, wanted to get feedback on what other changes would be needed.

Thanks!

[Yona-Appletree]

Thanks for this.... I've actually been looking forward to it for a while. I'd like to see it tested before I merge this in, however.

[anthonyn]

Hi,

So we just made this change and it looks good now, we had a weird flicker before, now its smooth animation.

Thanks,