mfd: twl-core: Fix passing of platform data in the device tree case

Since we still need to rely on a mix of device tree initialized
drivers and legacy platform data initialize drivers, let's fix
the passing of platform data to twl4030-gpio.

As the twl4030 GPIO is initialized by twl-core.c, we need to register
the auxdata for twl4030 GPIO in twl-core.c.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>