viafb: via_i2c.c, via_i2c.h, viamode.c, viamode.h

via_i2c.c, via_i2c.h: Implement i2c specification.
viamode.c, viamode.c: all support modes information.

Signed-off-by: Joseph Chan <josephchan@via.com.tw>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>