twl4030 uses gpiolib

Two patches follow ... they go on top of (a) the four from Felipe, which he's updating to move the twl_has_XYZ() macros into the core;
(b) the pullup tweak from Jagadeesh:

- Define and initialize platform data
- Be a platform_driver which uses that and gpiolib

There's more work to be done, but this is IMO a good start and seems mergeable as-is.

- Dave