ARM: mvebu: add function to set the resume boot address for Armada 375

In order to boot the secondary CPUs on Armada 375, we need to set the
boot address of these CPUs, through a register part of the System
Controller (this deviates from the Armada XP design, where the boot
address was defined using a register part of the PMSU unit).

Therefore, this commit adds a new helper function in the System
Controller driver to set the secondary CPU boot address.

Moreover, it moves the System Controller initialization as an
early_initcall(), since arch_initcall() is too late for an SMP-related
initialization.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483648-26611-7-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483648-26611-7-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>