ARM: dove: add cpu device tree node

This adds a node for the Marvell Sheeva PJ4A CPU found on Dove SoCs.
While at it, also move the l2-cache node out of internal registers and
consistently name different nodes.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

Conflicts:
	arch/arm/boot/dts/dove.dtsi