s3cfb: Add v0 gamma tuning hack

This is based on supercurio's Voodoo color with these differences:
  - Fixed a bug which causes the screen to display strange color at
    near-dim brightness
  - The values used are positive integers
  - The default is no tuning

Conflicts:
	drivers/video/samsung/s3cfb_tl2796.c
s3cfb: Rename v0 (actually v1) gamma hack to match crespo

Conflicts:
	drivers/video/samsung/s3cfb_tl2796.c