arm/dt: msm8974-liquid: Add SMB210 5 V regulator device

Add a device node for MSM8974 LIQUID to provide control of the
SMB210 regulator which supplies 5 V to various onboard devices.

The SMB210 regulator (named "ext_5v") is controlled via PM8941
MPP 2.  Add initial configurations for this MPP so that it can
be used to successfully enable and disable the regulator.

Modify the parent-supply property of regulators pm8941_mvs1 and
pm8941_mvs2 to point at the ext_5v regulator.  This is needed
because these regulators are supplied by ext_5v on MSM8974 LIQUID
as opposed to by pm8941_boost on other MSM8974 boards.

Change-Id: I62bee4eaafb4508521b547f1e1aea4f2fb4fae53
Signed-off-by: David Collins <collinsd@codeaurora.org>
diff --git a/arch/arm/boot/dts/msm8974-liquid.dts b/arch/arm/boot/dts/msm8974-liquid.dts
index bf4adaf..d742fe4 100644
--- a/arch/arm/boot/dts/msm8974-liquid.dts
+++ b/arch/arm/boot/dts/msm8974-liquid.dts
@@ -54,6 +54,21 @@
 			debounce-interval = <15>;
 		};
 	};
+
+	ext_5v: regulator-smb210 {
+		compatible = "regulator-fixed";
+		regulator-name = "ext_5v";
+		gpio = <&pm8941_mpps 2 0>;
+		enable-active-high;
+	};
+};
+
+&pm8941_mvs1 {
+	parent-supply = <&ext_5v>;
+};
+
+&pm8941_mvs2 {
+	parent-supply = <&ext_5v>;
 };
 
 &pm8941_gpios {
@@ -201,6 +216,12 @@
 	};
 
 	mpp@a100 { /* MPP 2 */
+		/* ext_5v regulator enable */
+		qcom,mode = <1>; /* Digital output */
+		qcom,invert = <0>; /* Output low initially */
+		qcom,vin-sel = <2>; /* PM8941 S3 = 1.8 V */
+		qcom,src-select = <0>; /* Constant */
+		qcom,master-en = <1>; /* Enable MPP */
 	};
 
 	mpp@a200 { /* MPP 3 */