i2c: core: Pick i2c bus number from ACPI if present

Under LoongARCH based on ACPI(such as Loongson-3A + LS7A), the ls2x i2c
driver obtains the i2c bus number from ACPI table.

Similar to the DT-base system, this is also a static bus number.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>

drivers/i2c/i2c-core-base.c

@@ -1555,14 +1555,22 @@ static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
 int i2c_add_adapter(struct i2c_adapter *adapter)
 {
 	struct device *dev = &adapter->dev;
-	int id;
+	acpi_status status;
+	unsigned long long id;
 
 	if (dev->of_node) {
 		id = of_alias_get_id(dev->of_node, "i2c");
 		if (id >= 0) {
 			adapter->nr = id;
 			return __i2c_add_numbered_adapter(adapter);
 		}
+	} else if (dev->parent->fwnode) {
+		status = acpi_evaluate_integer(ACPI_HANDLE(dev->parent),
+						"_UID", NULL, &id);
+		if (ACPI_SUCCESS(status) && (id >= 0)) {
+			adapter->nr = id;
+			return __i2c_add_numbered_adapter(adapter);
+		}
 	}
 
 	mutex_lock(&core_lock);