phy: ti-pipe3: Add clocks to PIPE3 PHY Documentation binding

   filled in "reg".

 - #phy-cells: determine the number of cells that should be given in the

   phandle while referencing this phy.

 - clocks: a list of phandles and clock-specifier pairs, one for each entry in

   clock-names.

 - clock-names: should include:

   * "wkupclk" - wakeup clock.

   * "sysclk" - system clock.

   * "refclk" - reference clock.

Optional properties:

 - ctrl-module : phandle of the control module used by PHY driver to power on

	reg-names = "phy_rx", "phy_tx", "pll_ctrl";

	ctrl-module = <&omap_control_usb>;

	#phy-cells = <0>;

	clocks = <&usb_phy_cm_clk32k>,

		 <&sys_clkin>,

		 <&usb_otg_ss_refclk960m>;

	clock-names =	"wkupclk",

			"sysclk",

			"refclk";

};