dt-bindings: usb: mtk-xhci: remove dummy clocks and add optional ones

Remove dummy clocks for usb wakeup and add optional ones for
MCU_BUS_CK and DMA_BUS_CK.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/mediatek,mtk-xhci.txt

@@ -26,10 +26,11 @@ Required properties:
  - clocks : a list of phandle + clock-specifier pairs, one for each
 	entry in clock-names
  - clock-names : must contain
-	"sys_ck": for clock of xHCI MAC
-	"ref_ck": for reference clock of xHCI MAC
-	"wakeup_deb_p0": for USB wakeup debounce clock of port0
-	"wakeup_deb_p1": for USB wakeup debounce clock of port1
+	"sys_ck": controller clock used by normal mode,
+	the following ones are optional:
+	"ref_ck": reference clock used by low power mode etc,
+	"mcu_ck": mcu_bus clock for register access,
+	"dma_ck": dma_bus clock for data transfer by DMA
 
  - phys : a list of phandle + phy specifier pairs
 
@@ -57,9 +58,7 @@ usb30: usb@11270000 {
 	clocks = <&topckgen CLK_TOP_USB30_SEL>, <&clk26m>,
 		 <&pericfg CLK_PERI_USB0>,
 		 <&pericfg CLK_PERI_USB1>;
-	clock-names = "sys_ck", "ref_ck",
-		      "wakeup_deb_p0",
-		      "wakeup_deb_p1";
+	clock-names = "sys_ck", "ref_ck";
 	phys = <&phy_port0 PHY_TYPE_USB3>,
 	       <&phy_port1 PHY_TYPE_USB2>;
 	vusb33-supply = <&mt6397_vusb_reg>;
@@ -91,9 +90,8 @@ Required properties:
 
  - clocks : a list of phandle + clock-specifier pairs, one for each
 	entry in clock-names
- - clock-names : must be
-	"sys_ck": for clock of xHCI MAC
-	"ref_ck": for reference clock of xHCI MAC
+ - clock-names : must contain "sys_ck", and the following ones are optional:
+	"ref_ck", "mcu_ck" and "dma_ck"
 
 Optional properties:
  - vbus-supply : reference to the VBUS regulator;