ARM: dts: kirkwood: set default pinctrl for SPI0

Most Kirkwood boards use the default SPI0 pinctrl setting anyway. Add a
default pinctrl setting to the toplevel SoC SPI0 node and put a note
in front of the corresponding pinctrl node to overwrite the setting
on board level.

Currently, only T5325 is using a different setting and already
overwrites the corresponding pinctrl node.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1398862602-29595-11-git-send-email-sebastian.hesselbarth@gmail.com


Signed-off-by: Jason Cooper <jason@lakedaemon.net>