ARM: shmobile: kzm9g-reference: Move pinctrl mappings to device tree

Replace the pinctrl mappings in board code by device tree mappings.
For devices that are still instantiated from board code reference the
mappings as the default pin controller state to apply them at boot time.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>