Enhancement: Support 3 output I/O with LPD6803_Pixel driver

```
Currently the LPD6803_Pixel driver only supports 1 I/O this needs to be 
extended to 4 to support an entire I/O header.


```

Original issue reported on code.google.com by `b...@byaroch.com` on 2 Jun 2011 at 8:41
