dts: fix 'colorway' compatibles

I can't find any reference anywhere showing that the manufacturer of
the LPD8803 or LPD8806 LED scripts is a company called 'colorway'.

Use 'greeled' instead; these seem to actually be manufactured by
GreeLed corporation.

Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>