usb: msm_otg: Update DT documentation for vbus_otg supply

vbus_otg is optional property that can be used to supply
VBUS in USB host mode.

Change-Id: I27b0ac0dbba909ae356c3133fbf4f8a76b9ae57d
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
diff --git a/Documentation/devicetree/bindings/usb/msm-hsusb.txt b/Documentation/devicetree/bindings/usb/msm-hsusb.txt
index d0886b0..c1d4a05 100644
--- a/Documentation/devicetree/bindings/usb/msm-hsusb.txt
+++ b/Documentation/devicetree/bindings/usb/msm-hsusb.txt
@@ -22,6 +22,10 @@
             1 - PHY control
 	    2 - PMIC control
 	    3 - User control (via debugfs)
+- <supply-name>-supply: handle to the regulator device tree node
+         Required "supply-name" is "HSUSB_VDDCX" (when voting for VDDCX) or
+         "hsusb_vdd_dig" (when voting for VDDCX Corner voltage),
+         "HSUSB_1p8-supply" and "HSUSB_3p3-supply".
 
 Optional properties :
 - qcom,hsusb-otg-disable-reset: If present then core is RESET only during
@@ -54,10 +58,8 @@
 	    Used for allowing USB to respond for remote wakup.
 - qcom,hsusb-otg-delay-lpm: If present then USB core will wait one second
 	after disconnect before entering low power mode.
-- <supply-name>-supply: handle to the regulator device tree node
-         Required "supply-name" is "HSUSB_VDDCX" (when voting for VDDCX) or
-         "hsusb_vdd_dig" (when voting for VDDCX Corner voltage),
-         "HSUSB_1p8-supply" and "HSUSB_3p3-supply".
+- <supply-name>-supply: handle to the regulator device tree node.
+         Optional "supply-name" is "vbus_otg" to supply vbus in host mode.
 - qcom,vdd-voltage-level: This property must be a list of three integer
 	values (no, min, max) where each value represents either a voltage
 	in microvolts or a value corresponding to voltage corner.