Add StarFive JH8100 dwmac support.
The JH8100 dwmac shares the same driver code as the JH7110 dwmac
and has only one reset signal.
Please refer to below:
  JH8100: reset-names = "stmmaceth";
  JH7110: reset-names = "stmmaceth", "ahb";
  JH7100: reset-names = "ahb";
Example usage of JH8100 in the device tree:
gmac0: ethernet@
16030000 {
        compatible = "starfive,jh8100-dwmac",
                     "starfive,jh7110-dwmac",
                     "snps,dwmac-5.20";
        ...
};
Signed-off-by: Tan Chun Hau <chunhau.tan@starfivetech.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20240403100549.78719-2-chunhau.tan@starfivetech.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
       - items:
           - const: starfive,jh7110-dwmac
           - const: snps,dwmac-5.20
+      - items:
+          - const: starfive,jh8100-dwmac
+          - const: starfive,jh7110-dwmac
+          - const: snps,dwmac-5.20
 
   reg:
     maxItems: 1
           minItems: 3
           maxItems: 3
 
-        resets:
-          minItems: 2
-
-        reset-names:
-          minItems: 2
+      if:
+        properties:
+          compatible:
+            contains:
+              const: starfive,jh8100-dwmac
+      then:
+        properties:
+          resets:
+            maxItems: 1
+
+          reset-names:
+            const: stmmaceth
+      else:
+        properties:
+          resets:
+            minItems: 2
+
+          reset-names:
+            minItems: 2
 
 unevaluatedProperties: false