dt-bindings: net: starfive,jh7110-dwmac: Add StarFive JH8100 support

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>