dt-bindings: pci: apple,pcie: Drop max-link-speed from example

We no longer use these since 111659c2 (and they never worked
anyway); drop them from the example to avoid confusion.

Fixes: 111659c2 ("arm64: dts: apple: t8103: Remove PCIe max-link-speed properties")
Signed-off-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220502091308.28233-1-marcan@marcan.st

Documentation/devicetree/bindings/pci/apple,pcie.yaml

@@ -142,7 +142,6 @@ examples:
           device_type = "pci";
           reg = <0x0 0x0 0x0 0x0 0x0>;
           reset-gpios = <&pinctrl_ap 152 0>;
-          max-link-speed = <2>;
 
           #address-cells = <3>;
           #size-cells = <2>;
@@ -153,7 +152,6 @@ examples:
           device_type = "pci";
           reg = <0x800 0x0 0x0 0x0 0x0>;
           reset-gpios = <&pinctrl_ap 153 0>;
-          max-link-speed = <2>;
 
           #address-cells = <3>;
           #size-cells = <2>;
@@ -164,7 +162,6 @@ examples:
           device_type = "pci";
           reg = <0x1000 0x0 0x0 0x0 0x0>;
           reset-gpios = <&pinctrl_ap 33 0>;
-          max-link-speed = <1>;
 
           #address-cells = <3>;
           #size-cells = <2>;