samples: sensor: ccs811: 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/ccs811/src/main.c b/samples/sensor/ccs811/src/main.c
index 74e579a..6862c67 100644
--- a/samples/sensor/ccs811/src/main.c
+++ b/samples/sensor/ccs811/src/main.c
@@ -113,12 +113,12 @@
 
 void main(void)
 {
-	const struct device *dev = device_get_binding(DT_LABEL(DT_INST(0, ams_ccs811)));
+	const struct device *dev = DEVICE_DT_GET_ONE(ams_ccs811);
 	struct ccs811_configver_type cfgver;
 	int rc;
 
-	if (!dev) {
-		printk("Failed to get device binding");
+	if (!device_is_ready(dev)) {
+		printk("Device %s is not ready\n", dev->name);
 		return;
 	}