clk: hisilicon: add hi3620_mmc_clks

Suggest by Arnd: abstract mmc tuning as clock behavior,
also because different soc have different tuning method and registers.
hi3620_mmc_clks is added to handle mmc clock specifically on hi3620.

Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
diff --git a/Documentation/devicetree/bindings/arm/hisilicon/hisilicon.txt b/Documentation/devicetree/bindings/arm/hisilicon/hisilicon.txt
index 8c7a465..df0a452 100644
--- a/Documentation/devicetree/bindings/arm/hisilicon/hisilicon.txt
+++ b/Documentation/devicetree/bindings/arm/hisilicon/hisilicon.txt
@@ -30,3 +30,17 @@
 		resume-offset = <0x308>;
 		reboot-offset = <0x4>;
 	};
+
+PCTRL: Peripheral misc control register
+
+Required Properties:
+- compatible: "hisilicon,pctrl"
+- reg: Address and size of pctrl.
+
+Example:
+
+	/* for Hi3620 */
+	pctrl: pctrl@fca09000 {
+		compatible = "hisilicon,pctrl";
+		reg = <0xfca09000 0x1000>;
+	};