- Remove OFDEVICE dependency from PINCTRL. It won't do
  much then, so add a comment to Kconfig when PINCTRL is
  selected without OFDEVICE
- Let Architectures only select PINCTRL instead of the
  particular driver. Change the drivers to 'default y if $SOC'
  to make sure the drivers are still compiled if the corresponding
  SoC is selected

This fixes Kconfig warnings like:

warning: (PINCTRL_ARMADA_370 && PINCTRL_ARMADA_XP && PINCTRL_DOVE && PINCTRL_KIRKWOOD) selects PINCTRL which has unmet direct dependencies (OFDEVICE)

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>