gpio: loongson: Fix Loongson-2K2000 ACPI GPIO register offset

gpio: loongson: Fix Loongson-2K2000 ACPI GPIO register offset

Since commit 3feb70a61740 ("gpio: loongson: add more gpio chip
support"), the Loongson-2K2000 GPIO is supported.

However, according to the firmware development specification, the
Loongson-2K2000 ACPI GPIO register offsets in the driver do not match
the register base addresses in the firmware, resulting in the registers
not being accessed properly.

Now, we fix it to ensure the GPIO function works properly.

Cc: stable@vger.kernel.org
Cc: Yinbo Zhu <zhuyinbo@loongson.cn>
Fixes: 3feb70a61740 ("gpio: loongson: add more gpio chip support")
Co-developed-by: Hongliang Wang <wanghongliang@loongson.cn>
Signed-off-by: Hongliang Wang <wanghongliang@loongson.cn>
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://lore.kernel.org/r/20250107103856.1037222-1-zhoubinbin@loongson.cn
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>