dt-bindings: phy: sun4i-usb-phy: Add property descriptions for H3

The Allwinner H3 SoC has 4 USB PHYs, so it needs four sets of pmu
regions, clocks, resets, and optional vbus properties. These were
not described when the H3 compatible string was added.

Fixes: 626a630e ("phy-sun4i-usb: Add support for the host usb-phys
		      found on the H3 SoC")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Documentation/devicetree/bindings/phy/sun4i-usb-phy.txt

@@ -17,18 +17,21 @@ Required properties:
   * "phy_ctrl"
   * "pmu0" for H3, V3s and A64
   * "pmu1"
-  * "pmu2" for sun4i, sun6i or sun7i
+  * "pmu2" for sun4i, sun6i, sun7i or sun8i-h3
+  * "pmu3" for sun8i-h3
 - #phy-cells : from the generic phy bindings, must be 1
 - clocks : phandle + clock specifier for the phy clocks
 - clock-names :
   * "usb_phy" for sun4i, sun5i or sun7i
   * "usb0_phy", "usb1_phy" and "usb2_phy" for sun6i
   * "usb0_phy", "usb1_phy" for sun8i
+  * "usb0_phy", "usb1_phy", "usb2_phy" and "usb3_phy" for sun8i-h3
 - resets : a list of phandle + reset specifier pairs
 - reset-names :
   * "usb0_reset"
   * "usb1_reset"
-  * "usb2_reset" for sun4i, sun6i or sun7i
+  * "usb2_reset" for sun4i, sun6i, sun7i or sun8i-h3
+  * "usb3_reset" for sun8i-h3
 
 Optional properties:
 - usb0_id_det-gpios : gpio phandle for reading the otg id pin value
@@ -37,6 +40,7 @@ Optional properties:
 - usb0_vbus-supply : regulator phandle for controller usb0 vbus
 - usb1_vbus-supply : regulator phandle for controller usb1 vbus
 - usb2_vbus-supply : regulator phandle for controller usb2 vbus
+- usb3_vbus-supply : regulator phandle for controller usb3 vbus
 
 Example:
 	usbphy: phy@0x01c13400 {