i2c: nomadik: Add default configuration into the Nomadik I2C driver

At this moment in time there is only one known configuration for the
Nomadik I2C driver. By not holding that configuration in the driver
adds some unnecessary overhead in platform code. The configuration
has already been removed from platform code, this patch checks for any
over-riding configurations. If there aren't any, the default is used.

[LinusW says: "Right now this is causing boot regressions so we need it
badly..."]

Acked-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>