ARM: zynq: PM: Enable DDR clock stop

The DDR controller can detect idle periods and leverage low power
features clock stop. When new requests occur, the DDRC resumes
normal operation.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --cc arch/arm/mach-zynq/Makefile
Simple merge

diff --cc arch/arm/mach-zynq/common.c
Simple merge

diff --cc arch/arm/mach-zynq/common.h
Simple merge

diff --cc arch/arm/mach-zynq/pm.c
Simple merge