i2c: i2c-s3c2410: Initialise Samsung I2C controller early

This is required in order to ensure that core system devices such as
voltage regulators attached via I2C are avaiable early in boot.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>