Add support for building the WS2812 LED strip driver sample against
the new ws2812b_sw driver. Currently a configuration is only provided
for the BBC micro:bit board.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This is similar to the LPD8806 sample, but uses the WS2812 driver
instead. The app configuration is a bit more finicky, so try to
provide helpful references. This could be made more beginner-friendly
with the addition of timing diagrams, etc., but this should be enough
for an experienced developer to use.
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>