drivers: regulator: fix getting gpio for level control

Swap the 2 calls to find gpio property in "regulator-gpio" compiatble
node. Obviously the first call expects to get the GPIO resource
while the second check that the node does not define 2 or more GPIOs
to control the regulator level as the implementation only supports one,
as described in the inline comment.

Fixes: f164f0f ("drivers: regulator: GPIO controlled regulator")
Signed-off-by: Etienne Carriere <[email protected]>

core/drivers/regulator/regulator_gpio.c

@@ -148,6 +148,11 @@ static TEE_Result get_voltage_level_gpio(const void *fdt, int node,
 	void *gpio_ref = &gpio;
 	int len = 0;
 
+	res = dt_driver_device_from_node_idx_prop("gpios", fdt, node, 0,
+						  DT_DRIVER_GPIO, gpio_ref);
+	if (res)
+		return res;
+
 	/*
 	 * DT bindings allows more than 1 GPIO to control more than
 	 * 2 voltage levels. As it's not used so far in known platforms
@@ -161,11 +166,6 @@ static TEE_Result get_voltage_level_gpio(const void *fdt, int node,
 		return TEE_ERROR_GENERIC;
 	}
 
-	res = dt_driver_device_from_node_idx_prop("gpios", fdt, node, 0,
-						  DT_DRIVER_GPIO, gpio_ref);
-	if (res)
-		return res;
-
 	cuint = fdt_getprop(fdt, node, "states", &len);
 	if (!cuint || len != 4 * sizeof(fdt32_t)) {
 		EMSG("Node %s expects 2 levels from property \"states\"",