* Generalize GPIO handling.
* Add libs to configure gpio's clocks and pads
* Add Interrupt handling.
* Introduce mmio.h and log.h
Change-Id: I928e4c807d15031de2eede4b3ecff62df795f8ac
Small GPIO driver that exports a few pins using a virtual file
system. Currently the two user leds and the user button are exported.
Change-Id: I001d017ae27cd17b635587873f7da981054da459