ARM: mvebu: armada-xp: Add node alias to pinctrl and add base address

In other MVEBU SoCs, the pin controller node is called pin-ctrl with
its base address added. Also, we have a node alias to access the pinctrl
node easily. Fix this for Armada XP pinctrl nodes to be consistent with
other SoCs.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-By: Benoit Masson <yahoo@perenite.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>