The current pinctrl functions were a mess. Normalise the functions
names to make them shorter and clearer.
Change-Id: Iac6ff84625ef2b7610268e3a5802dc0088de3167
Past development has proved that one can mistakely use
the same pin for two uses without noticing. Since this
causes extremely hard to find bugs, the infrastructure
will allow to register pin uses and panic when a conflict
is detected. The pinctrl debug now shows the pin uses
when its support is compiled in.
Change-Id: Idb2d5235ce09207d77aa474d6f158e72b933761a