dt-bindings: devfreq: rk3399_dmc: Add rockchip,pmu phandle

The Rockchip DMC (Dynamic Memory Interface) needs to access to the PMU
general register files to know the DRAM type, so add a phandle to the
syscon that manages these registers.
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Gaël PORTAY <gael.portay@collabora.com>
Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

Documentation/devicetree/bindings/devfreq/rk3399_dmc.txt

@@ -18,6 +18,8 @@ Optional properties:
 			 format depends on the interrupt controller.
 			 It should be a DCF interrupt. When DDR DVFS finishes
 			 a DCF interrupt is triggered.
+- rockchip,pmu:		 Phandle to the syscon managing the "PMU general register
+			 files".
 
 Following properties relate to DDR timing: