[PATCH] I2C: Make i2c_add_driver automatically set the proper module owner

This prevents i2c drivers from messing up and forgetting to set the
module owner of their driver.  It also reduces the size of their drivers
by one line :)

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jean Delvare <khali@linux-fr.org>