ARM: mvebu: make the cpuidle initialization more generic

In preparation to the addition of the cpuidle support for more SoCs,
this patch moves the Armada XP specific initialization to a separate
function.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1406120453-29291-7-git-send-email-thomas.petazzoni@free-electrons.com


Signed-off-by: Jason Cooper <jason@lakedaemon.net>