tdfxfb: move I2C functionality into the tdfxfb

The I2C functionality provided by the i2c-voodoo3 driver is moved into the
tdfxfb (frame buffer driver for Voodoo3 cards).  This way there is no
conflict between the i2c driver and the fb driver.

The tdfxfb does not make use from the DDC functionality yet but provides
all the functionality of the i2c-voodoo3 driver.

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>