ARM: mvebu: add SMP support for Armada 375 and Armada 38x

ARM: mvebu: add SMP support for Armada 375 and Armada 38x

This commit adds the SMP support for Armada 375 and Armada 38x. It
turns out that the SMP logic for both of these SOCs are fairly
similar, the only differences being:

 * A different method to set the secondary CPU boot address

 * An Armada 375 specific workaround needed for the early Z1 stepping,
   added by the following patch.

Other than that, the patch is fairly straightforward and adds the
usual platsmp and headsmp code, defining the smp_operations structure
that is referenced from the DT_MACHINE structures.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483648-26611-9-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483648-26611-9-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>