dt-bindings: net: snps,dwmac: modify available values of PBL

PBL can be any of the following values: 1, 2, 4, 8, 16 or 32
according to the datasheet, so modify available values of PBL in
snps,dwmac.yaml.
Signed-off-by: Biao Huang <biao.huang@mediatek.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220324012112.7016-2-biao.huang@mediatek.com

Documentation/devicetree/bindings/net/snps,dwmac.yaml

@@ -340,21 +340,21 @@ allOf:
           description:
             Programmable Burst Length (tx and rx)
           $ref: /schemas/types.yaml#/definitions/uint32
-          enum: [2, 4, 8]
+          enum: [1, 2, 4, 8, 16, 32]
 
         snps,txpbl:
           description:
             Tx Programmable Burst Length. If set, DMA tx will use this
             value rather than snps,pbl.
           $ref: /schemas/types.yaml#/definitions/uint32
-          enum: [2, 4, 8]
+          enum: [1, 2, 4, 8, 16, 32]
 
         snps,rxpbl:
           description:
             Rx Programmable Burst Length. If set, DMA rx will use this
             value rather than snps,pbl.
           $ref: /schemas/types.yaml#/definitions/uint32
-          enum: [2, 4, 8]
+          enum: [1, 2, 4, 8, 16, 32]
 
         snps,no-pbl-x8:
           $ref: /schemas/types.yaml#/definitions/flag