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.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>