ARM: mvebu: dts: remove unneeded linux,default-state from led nodes

Generally, power LEDs should indicate when power is applied, and go out
once power is removed.  _Not_ annoy the developer with migraine-inducing
blinking reminicent of some badly animated television series designed to
sell sugar to children.

On a more serious note, most of these OS-specific properties aren't
necessary and should be removed.  I left two that are legitimately tying
disk LEDs to disk activity.  Other than that, we keep the state the
bootloader left them in until userspace changes the state via sysfs.

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