dt-bindings: Fix missing '/schemas' in $ref paths

Absolute paths in $ref should always begin with '/schemas'. The tools
mostly work with it omitted, but for correctness the path should be
everything except the hostname as that is taken from the schema's $id
value. This scheme is defined in the json-schema spec.

Cc: Hector Martin <[e-mail]>
Cc: Sven Peter <[e-mail]>
Cc: Andrew Lunn <[e-mail]>
Cc: Vivien Didelot <[e-mail]>
Cc: Florian Fainelli <[e-mail]>
Cc: Vladimir Oltean <[e-mail]>
Cc: "David S. Miller" <[e-mail]>
Cc: Jakub Kicinski <[e-mail]>
Cc: Paolo Abeni <[e-mail]>
Cc: Mark Brown <[e-mail]>
Cc: Chunfeng Yun <[e-mail]>
Cc: Greg Kroah-Hartman <[e-mail]>
Cc: Mukesh Savaliya <[e-mail]>
Cc: Akash Asthana <[e-mail]>
Cc: Bayi Cheng <[e-mail]>
Cc: Chuanhong Guo <[e-mail]>
Cc: Min Guo <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Rob Herring <[e-mail]>
Acked-by: Jakub Kicinski <[e-mail]>
Acked-by: Mark Brown <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml

···
     description:
       The individual power management domains within this controller
     type: object
-    $ref: /power/apple,pmgr-pwrstate.yaml#
+    $ref: /schemas/power/apple,pmgr-pwrstate.yaml#
 
 required:
   - compatible

Documentation/devicetree/bindings/net/dsa/dsa-port.yaml

···
   Ethernet switch port Description
 
 allOf:
-  - $ref: "http://devicetree.org/schemas/net/ethernet-controller.yaml#"
+  - $ref: /schemas/net/ethernet-controller.yaml#
 
 properties:
   reg:

Documentation/devicetree/bindings/soc/qcom/qcom,geni-se.yaml

···
                  supports up to 50MHz, up to four chip selects, programmable
                  data path from 4 bits to 32 bits and numerous protocol
                  variants.
-    $ref: /spi/spi-controller.yaml#
+    $ref: /schemas/spi/spi-controller.yaml#
 
     properties:
       compatible:

Documentation/devicetree/bindings/spi/mediatek,spi-mtk-nor.yaml

···
   capability of this controller.
 
 allOf:
-  - $ref: /spi/spi-controller.yaml#
+  - $ref: /schemas/spi/spi-controller.yaml#
 
 properties:
   compatible:

Documentation/devicetree/bindings/spi/qcom,spi-qcom-qspi.yaml

···
   as NOR flash.
 
 allOf:
-  - $ref: /spi/spi-controller.yaml#
+  - $ref: /schemas/spi/spi-controller.yaml#
 
 properties:
   compatible:

Documentation/devicetree/bindings/spi/sprd,spi-adi.yaml

···
   compatibility.
 
 allOf:
-  - $ref: /spi/spi-controller.yaml#
+  - $ref: /schemas/spi/spi-controller.yaml#
 
 properties:
   compatible:

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

···
     default: host
 
   connector:
-    $ref: /connector/usb-connector.yaml#
+    $ref: /schemas/connector/usb-connector.yaml#
     description:
       Connector for dual role switch, especially for "gpio-usb-b-connector"
     type: object
···
 patternProperties:
   "^usb@[0-9a-f]+$":
     type: object
-    $ref: /usb/mediatek,mtk-xhci.yaml#
+    $ref: /schemas/usb/mediatek,mtk-xhci.yaml#
     description:
       The xhci should be added as subnode to mtu3 as shown in the following
       example if the host mode is enabled.

Documentation/devicetree/bindings/usb/mediatek,musb.yaml

···
     maxItems: 1
 
   connector:
-    $ref: /connector/usb-connector.yaml#
+    $ref: /schemas/connector/usb-connector.yaml#
     description: Connector for dual role switch
     type: object