[RFC 2.6.27] AM300 kit support

Hi Eric, Dmitry, Geert, Krzysztof, lak, input, fbdev,

This is my first pass at adding support for things on the AM300 kit from
E-Ink. The main two new things are the Wacom w8001 support and the
AM300/broadsheetfb display support. The other 3 patches are for cleanup.

There are still issues I intend to debug (latency on the display, usb
issues) but will lose access to the hardware for a while so this seems like
a good point to post the code. I would greatly appreciate your feedback.

Thanks,
jaya