ARM: mvebu: extend the PMSU registers

The initial binding for PMSU was wrong, as it didn't take into account
all the registers from the PMSU and moreover it referred to the CPU
reset registers which are not part of PMSU.

The Power Management Unit Service block also controls the Coherency
Fabric subsystem. These registers are needed for the CPU idle
implementation for the Armada 370/XP, it allows to enter a deep CPU
idle state where the Coherency Fabric and the L2 cache are powered
down.

This commit adds support for a new compatible for the PMSU node which
includes the registers related to the coherency fabric. It also keeps
compatibility with the old compatible string.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483433-25836-5-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483433-25836-5-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>