stmmac: loongson: Remove surplus loop

loongson_dwmac_probe() contains a loop which doesn't have an effect,
because it tries to call pcim_iomap_regions() with the same parameters
several times. The break statement at the loop's end furthermore ensures
that the loop only runs once anyways.

Remove the surplus loop.

Signed-off-by: Philipp Stanner <phasta@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Yanteng Si <si.yanteng@linux.dev>
Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Tested-by: Henry Chen <chenx97@aosc.io>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20250324092928.9482-4-phasta@kernel.org


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