pinctrl/nomadik: basic Nomadik pinctrl interface

This adds a scratch pin control interface to the Nomadik pinctrl
driver, and defines the pins and groups in the DB8500 ASIC. We
define GPIO ranges to cover the pins exposed. The DB8500 has
more pins than this but we restrict the driver to the pins that
can be controlled from the combined GPIO and pin control hardware
to begin with.

ChangeLog v1->v2:
- Base on the latest pinctrl development from
  pinctrl-mergebase-20120418 so we can get rid of legacy
  group count mechanism. Also drop the range checks for group
  index, this is handled by the core now.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>