leds: include the missing utils.h to pull in ARRAYLEN.

Signed-off-by: Michael Hope <mlhx@google.com>

src/main/drivers/light_led_stm32f30x.c

@@ -21,6 +21,8 @@
 
 #include "platform.h"
 
+#include "common/utils.h"
+
 #include "gpio.h"
 
 #include "light_led.h"