ARM: gic: Use cpu pm notifiers to save gic state

When the cpu is powered down in a low power mode, the gic cpu
interface may be reset, and when the cpu cluster is powered
down, the gic distributor may also be reset.

This patch uses CPU_PM_ENTER and CPU_PM_EXIT notifiers to save
and restore the gic cpu interface registers, and the
CPU_CLUSTER_PM_ENTER and CPU_CLUSTER_PM_EXIT notifiers to save
and restore the gic distributor registers.

Merge note:
Samsung had already applied the changes to struct gic_chip_data, although it
still remains in the .c file instead of having been moved to the header.

Original-author: Gary King <gking@nvidia.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-and-Acked-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>

Conflicts:
	arch/arm/include/asm/hardware/gic.h

Change-Id: I50b5cdd161637ff7b871ac5ffb30d669ec60c662
ARM: Exynos: Call cpu_pm_enter/exit in Low Power States.

In low power cpuidle states, the FPU registers get corrupted. By calling
cpu_pm_enter, the VFP module gets notified so that it saves the FPU state and
restores it from RAM the next time a thread uses it.

The comments at cpu_pm_enter/exit indicate that these functions must be called
with interrupts disabled, so place the calls between
local_irq_disable/local_irq_enble.

See http://forum.xda-developers.com/showthread.php?p=57637134 to
http://forum.xda-developers.com/showthread.php?p=57643086.

Change-Id: Icde0ab93734cf2a4febfabc3c04e77ce955bd9da