drivers: sensor: dht: Convert sample to use DEVICE_DT_GET_ONE

Move to use DEVICE_DT_GET_ONE instead of device_get_binding as
we work on phasing out use of DTS 'label' property.

Signed-off-by: Benjamin Björnsson <benjamin.bjornsson@gmail.com>
diff --git a/samples/sensor/dht/src/main.c b/samples/sensor/dht/src/main.c
index a9a39b8..d3460e9 100644
--- a/samples/sensor/dht/src/main.c
+++ b/samples/sensor/dht/src/main.c
@@ -32,11 +32,10 @@
 
 void main(void)
 {
-	const char *const label = DT_LABEL(DT_INST(0, aosong_dht));
-	const struct device *dht22 = device_get_binding(label);
+	const struct device *dht22 = DEVICE_DT_GET_ONE(aosong_dht);
 
-	if (!dht22) {
-		printf("Failed to find sensor %s\n", label);
+	if (!device_is_ready(dht22)) {
+		printf("Device %s is not ready\n", dht22->name);
 		return;
 	}