arm64: marvell: enable the Marvell PIC driver

This commit makes sure the driver for the Marvell PIC interrupt
controller (used on Marvell Armada 7K/8K) is enabled.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1470408921-447-4-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>