Add breathing sleep LED during USB suspend

common/sleep_led.h

@@ -0,0 +1,10 @@
+#ifndef SLEEP_LED_H
+#define SLEEP_LED_H
+
+#define NO_SUSPEND_POWER_DOWN
+
+void sleep_led_init(void);
+void sleep_led_enable(void);
+void sleep_led_disable(void);
+
+#endif