Add gpiod.c for libgpiod output sample code

guowenxue

2021-01-23 7baed996272cd3c889a5ab714c2b3391703f75f1

 modules/c/ds18b20.c

@@ -32,7 +32,7 @@
                return 1;
        }

        printf("DS19B20 get temperature: %f ℃\n", temp);
        printf("DS18B20 get temperature: %f ℃\n", temp);
        return 0;
}