A collection of changes that taken together makes the driver work correctly on
big-endian systems, specifically Sparc.

- Remove old PM2FB_BE_APERTURE define and use __BIG_ENDIAN
  throughout. PM2FB_BE_APERTURE wasn't defined on Sparc; this
  was incorrect.
- Replace colour mode magic numbers with suitable constants,
  and tidy colour mode handling. Use BGR not RGB at 24bit on
  big-endian.
- Replace aperture magic numbers with constants. Rearrange code to
  emphasise second aperture is not used. Add short explanations
  of aperture settings for big endian.
- Update comments to note that the driver now works on Sparc.
- Revisit 32bit depth colour offsets and ensure transp is set.
Signed-off-by: Jim Hague <jim.hague@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>