[LinuxBIOS] [PATCH] vt8237r fixes/improvements (LBv2)

[Corey Osgood]

This patch is some small changes to the vt8237r to prepare it for
the Jetway J7F2 patch that should be coming soon, and also moves most
defines into vt8237r.h. I've changed some of the values from u32 to u8,
because that's all they should ever need to be. Also includes
doxygenized comments!

Signed-off-by: Corey Osgood <corey.osgood at gmail.com>