ARM: mvebu: slightly refactor/rename PMSU idle related functions

ARM: mvebu: slightly refactor/rename PMSU idle related functions

The CPU hotplug code will need to call into PMSU functions to enter
and exit from deep idle states. However, the deep idle state is
currently entered by a function called do_armada_370_xp_cpu_suspend()
whose name really suggests it's an internal function, but we need to
export it to other files in mach-mvebu.

Therefore, this commit:

 * Merges the code of do_armada_370_xp_cpu_suspend() into
   armada_370_xp_pmsu_idle_prepare(), into a single function called
   armada_370_xp_pmsu_idle_enter(), which prepares the PMSU for deep
   idle, and then enters the deep idle state. This code will be common
   to both cpuidle and CPU hotplug.

 * For symetry, it renames the armada_370_xp_pmsu_idle_restore()
   function to armada_370_xp_pmsu_idle_exit().

We also remove the 'noinline' qualifier for these functions, which
apparently had no reason to be here.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1401481098-23326-3-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>