lxfb: Maintain video processor palette through suspend/resume

The Geode X driver uses both of the LX's palettes, one for gamma correction and one for colormaps.

The kernel driver currently only backs up the one used for colormaps during suspend/resume. If you mess with gamma settings and do a suspend/resume, colors go funny.

Fix this by backing up the video proc palette during suspend/resume, alongside the display controller one which is already handled.

Signed-off-by Daniel Drake <[email protected]>

Acked-by Andres Salomon <[email protected]>