dt-bindings: PCI: toshiba,tc9563: Restrict Tx Amplitude, DFE and N_FTS to USP, DSP1 and DSP2

TC9563 switch allows configuring Tx Amplitude, DFE and N_FTS settings only
to USP, DSP1 and DSP2 ports. These settings don't apply to DSP3 or the
integrated Ethernet MAC Endpoint.

Restrict these properties and move 'toshiba,tx-amplitude-microvolt' to DSP2
in the example to conform to the binding.

Fixes: 26f3ac8848 ("dt-bindings: PCI: Add binding for Toshiba TC9563 PCIe switch")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Elder <elder@riscstar.com>
Link: https://patch.msgid.link/20260725-tc9563-fix-v1-1-ec4286e31331@oss.qualcomm.com

Documentation/devicetree/bindings/pci/toshiba,tc9563.yaml

@@ -54,7 +54,7 @@ properties:
           - description: I2C slave address
 
 patternProperties:
-  "^pcie@[1-3],0$":
+  "^pcie@[1-2],0$":
     description:
       child nodes describing the internal downstream ports of
       the tc9563 switch.
@@ -64,6 +64,21 @@ patternProperties:
       - $ref: /schemas/pci/pci-pci-bridge.yaml#
     unevaluatedProperties: false
 
+  "^pcie@[3],0$":
+    description:
+      child node describing the internal downstream port connected to the
+      integrated Ethernet MAC endpoint of the tc9563 switch.
+    type: object
+    $ref: /schemas/pci/pci-pci-bridge.yaml#
+    properties:
+      n-fts: false
+    patternProperties:
+      "^ethernet@0,[0-1]$":
+        type: object
+        properties:
+          n-fts: false
+    unevaluatedProperties: false
+
 $defs:
   tc9563-node:
     type: object
@@ -154,6 +169,8 @@ examples:
                     device_type = "pci";
                     ranges;
                     bus-range = <0x04 0xff>;
+
+                    toshiba,tx-amplitude-microvolt = <10>;
                 };
 
                 pcie@3,0 {
@@ -165,8 +182,6 @@ examples:
                     ranges;
                     bus-range = <0x05 0xff>;
 
-                    toshiba,tx-amplitude-microvolt = <10>;
-
                     ethernet@0,0 {
                         reg = <0x50000 0x0 0x0 0x0 0x0>;
                     };