net: stmmac: dwmac-loongson: Add fix_soc_reset() callback

Loongson's DWMAC device may take nearly two seconds to complete DMA reset,
however, the default waiting time for reset is 200 milliseconds.
Therefore, the following error message may appear:

[14.427169] dwmac-loongson-pci 0000:00:03.2: Failed to reset the dma

Fixes: 803fc61d ("net: stmmac: dwmac-loongson: Add Loongson Multi-channels GMAC support")
Cc: stable@vger.kernel.org
Signed-off-by: Qunqin Zhao <zhaoqunqin@loongson.cn>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Yanteng Si <si.yanteng@linux.dev>
Link: https://patch.msgid.link/20250219020701.15139-1-zhaoqunqin@loongson.cn


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