omap4: splitting padconfs into common, 4430 and 4460

omap4: splitting padconfs into common, 4430 and 4460

Not all padconfs are the same between 4430 and 4460, so instead of
working around this with an if, we should have an specific padconf
structure for both chips (like handling the differences between the LEDs
GPIOs and TPS).

Signed-off-by: Ricardo Salveti de Araujo <ricardo.salveti@linaro.org>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>