mbxfb: Improvements and new features

This contains the following changes:

* Overlay surface alpha is configured separately from the overlay. This
prevents display glitches (configure and fill the overlay first, set
alpha to a visible value next)

* Added an ioctl for configuring transparency of the Overlay and graphics
planes. Blend mode, colorkey mode and global alpha mode are supported.

* Added an ioctl for setting the plane order. The overlay plance can be placed
over or
under the graphics plane.

* Added an ioctl for setting and reading chip registers, with mask.

* Updated copyright for 2007

[adaplas]
* Coding style changes

Signed-off-by: Raphael Assenat <raph@8d.com>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>