dt-bindings: PCI: snps,dw-pcie-ep: Drop conflicting 'max-functions' schema

'max-functions' is already defined in pci-ep.yaml schema as a uint8 and all
users of it expect an uint8. Drop the conflicting schema.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220107030358.2378221-1-robh@kernel.org

Documentation/devicetree/bindings/pci/snps,dw-pcie-ep.yaml

@@ -64,10 +64,6 @@ properties:
     maxItems: 1
     deprecated: true
 
-  max-functions:
-    $ref: /schemas/types.yaml#/definitions/uint32
-    description: maximum number of functions that can be configured
-
 required:
   - reg
   - reg-names