dt: ar803x: document SmartEEE properties

The SmartEEE feature of Atheros AR803x PHYs can cause the link to
bounce. Add DT properties to allow SmartEEE to be disabled, and to
allow the Tw parameters for 100M and 1G links to be configured.

Signed-off-by: Russell King <[e-mail]>
Reviewed-by: Rob Herring <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

Documentation/devicetree/bindings/net/qca,ar803x.yaml

···
     $ref: /schemas/types.yaml#/definitions/uint32
     enum: [0, 1, 2]
 
+  qca,disable-smarteee:
+    description: Disable Atheros SmartEEE feature.
+    type: boolean
+
   qca,keep-pll-enabled:
     description: |
       If set, keep the PLL enabled even if there is no link. Useful if you
···
 
       Only supported on the AR8031.
     type: boolean
+
+  qca,smarteee-tw-us-100m:
+    description: EEE Tw parameter for 100M links.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 255
+
+  qca,smarteee-tw-us-1g:
+    description: EEE Tw parameter for gigabit links.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    minimum: 1
+    maximum: 255
 
   vddio-supply:
     description: |