acpi: Correct reset handling in acpi_device_add_power_res()

If there is no reset line, this still emits ACPI code for the reset GPIO.
Fix it by updating the check.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/lib/acpi/acpi_device.c b/lib/acpi/acpi_device.c
index 95dfac5..c3439a5 100644
--- a/lib/acpi/acpi_device.c
+++ b/lib/acpi/acpi_device.c
@@ -422,7 +422,7 @@
 
 	/* Method (_ON, 0, Serialized) */
 	acpigen_write_method_serialized(ctx, "_ON", 0);
-	if (reset_gpio) {
+	if (has_reset) {
 		ret = acpigen_set_enable_tx_gpio(ctx, tx_state_val, dw0_read,
 						 dw0_write, &reset, true);
 		if (ret)