cirrusfb: various improvements

Various improvements to the code:
- kill a structure with only one
  field: multiplexing and use the
  field directly
- move the cirrusfb_ops structure
  down the file to kill forward
  declarations
- move cirrusfb_init() to kill
  forward declaration
- kill register loads done already
  in the init_vgachip()
- kill assigments done by higher
  layer in the cirrusfb_pan_display()
- do not overwrite line pitch bit in
  the CL_CRT1D register
- kill btype variables if they were
  used only once or twice
- add cpu_relax() in the busy waiting
  loop

The fix to the CL_CRT1D register handling makess the 1024x768 32bpp mode
work.  Previously, only lower resolution modes have worked with 32bpp.
Signed-off-by: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>