[PATCH] fbcon: Add ability to save/restore graphics state

Add hooks to save and restore the graphics state.  These hooks are called in
fbcon_blank() when entering/leaving KD_GRAPHICS mode.  This is needed by
savagefb at least so it can cooperate with savage_dri and by cyblafb.

State save/restoration can be full or partial.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>