Add device definition and support functions for the
second i2c device (i2c1). If this is selected, the first
i2c bus will become index 0 instead of index -1.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

Make the device i2c0 common to plat-s3c and move the
definitions from arch/arm/plat-s3c24xx/devs.c
Signed-off-by: NBen Dooks <ben-linux@fluff.org>