dt-bindings: mmc: sdhci-msm: Add interconnect BW scaling strings

Add interconnect bandwidth scaling supported strings for qcom-sdhci
controller.

Signed-off-by: Pradeep P V K <ppvk@codeaurora.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1591691846-7578-3-git-send-email-ppvk@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/sdhci-msm.txt

@@ -54,6 +54,21 @@ Required properties:
 - qcom,dll-config: Chipset and Platform specific value. Use this field to
 	specify the DLL_CONFIG register value as per Hardware Programming Guide.
 
+Optional Properties:
+* Following bus parameters are required for interconnect bandwidth scaling:
+- interconnects: Pairs of phandles and interconnect provider specifier
+		 to denote the edge source and destination ports of
+		 the interconnect path.
+
+- interconnect-names: For sdhc, we have two main paths.
+		1. Data path : sdhc to ddr
+		2. Config path : cpu to sdhc
+		For Data interconnect path the name supposed to be
+		is "sdhc-ddr" and for config interconnect path it is
+		"cpu-sdhc".
+		Please refer to Documentation/devicetree/bindings/
+		interconnect/ for more details.
+
 Example:
 
 	sdhc_1: sdhci@f9824900 {
@@ -71,6 +86,9 @@ Example:
 
 		clocks = <&gcc GCC_SDCC1_APPS_CLK>, <&gcc GCC_SDCC1_AHB_CLK>;
 		clock-names = "core", "iface";
+		interconnects = <&qnoc MASTER_SDCC_ID &qnoc SLAVE_DDR_ID>,
+				<&qnoc MASTER_CPU_ID &qnoc SLAVE_SDCC_ID>;
+		interconnect-names = "sdhc-ddr","cpu-sdhc";
 
 		qcom,dll-config = <0x000f642c>;
 		qcom,ddr-config = <0x80040868>;