ARM: dts: kirkwood: set default pinctrl for NAND

There is only one valid pinctrl setting for NAND on Kirkwood. Now that we
have the setting in the common SoC pinctrl, move it to the NAND controller
node directly and remove it from the individual boards.

While at it, also fix up status = "okay" to "ok" on one board's NAND node.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1398862602-29595-12-git-send-email-sebastian.hesselbarth@gmail.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>