dt-bindings: usb: Fix references to usb-hcd.yaml

usb-hcd.txt has been converted to YAML. Update references accordingly.

Fixes: 14ec072a ("dt-bindings: usb: Convert USB HCD generic binding to YAML")
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20191003193132.17758-1-j.neuschaefer@gmx.netSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -33,7 +33,7 @@ Required properties:
 	"dma_ck": dma_bus clock for data transfer by DMA,
 	"xhci_ck": controller clock
 
- - phys : see usb-hcd.txt in the current directory
+ - phys : see usb-hcd.yaml in the current directory
 
 Optional properties:
  - wakeup-source : enable USB remote wakeup;
@@ -53,7 +53,7 @@ Optional properties:
 	See: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
  - imod-interval-ns: default interrupt moderation interval is 5000ns
 
-additionally the properties from usb-hcd.txt (in the current directory) are
+additionally the properties from usb-hcd.yaml (in the current directory) are
 supported.
 
 Example:

Documentation/devicetree/bindings/usb/mediatek,mtu3.txt

@@ -17,7 +17,7 @@ Required properties:
  - clock-names : must contain "sys_ck" for clock of controller,
 	the following clocks are optional:
 	"ref_ck", "mcu_ck" and "dma_ck";
- - phys : see usb-hcd.txt in the current directory
+ - phys : see usb-hcd.yaml in the current directory
  - dr_mode : should be one of "host", "peripheral" or "otg",
 	refer to usb/generic.txt
 
@@ -60,7 +60,7 @@ Optional properties:
  - mediatek,u3p-dis-msk : mask to disable u3ports, bit0 for u3port0,
 	bit1 for u3port1, ... etc;
 
-additionally the properties from usb-hcd.txt (in the current directory) are
+additionally the properties from usb-hcd.yaml (in the current directory) are
 supported.
 
 Sub-nodes:

Documentation/devicetree/bindings/usb/usb-uhci.txt

@@ -6,7 +6,7 @@ Required properties:
 - reg : Should contain 1 register ranges(address and length)
 - interrupts : UHCI controller interrupt
 
-additionally the properties from usb-hcd.txt (in the current directory) are
+additionally the properties from usb-hcd.yaml (in the current directory) are
 supported.
 
 Example:

Documentation/devicetree/bindings/usb/usb-xhci.txt

@@ -41,9 +41,9 @@ Optional properties:
   - usb3-lpm-capable: determines if platform is USB3 LPM capable
   - quirk-broken-port-ped: set if the controller has broken port disable mechanism
   - imod-interval-ns: default interrupt moderation interval is 5000ns
-  - phys : see usb-hcd.txt in the current directory
+  - phys : see usb-hcd.yaml in the current directory
 
-additionally the properties from usb-hcd.txt (in the current directory) are
+additionally the properties from usb-hcd.yaml (in the current directory) are
 supported.