i2c-ibm_iic: Add support for new-style clients

Use i2c_bit_add_numbered_adapter() if device id specified, so that the
i2c-ibm_iic adapter works well with new-style pre-declared devices.

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>