Add mozc double sided version.

Change-Id: I3c50b5c3435c3c01c79bfc14c5d605701a423356
Co-authored-by: Takashi Toyoshima <toyoshim@google.com>
Co-authored-by: Shun Ikejima <ikejima@google.com>
Reviewed-by: Eliot Courtney <edcourtney@google.com>

mozc-doublesided/firmware/Core/Inc/led.h

@@ -0,0 +1,13 @@
+// Copyright 2024 Google Inc.
+// Use of this source code is governed by an Apache License that can be found in
+// the LICENSE file.
+
+#ifndef LED_H_
+#define LED_H_
+
+#include <stdint.h>
+
+void led_set(uint8_t index, uint8_t r, uint8_t g, uint8_t b);
+void led_flush(void);
+
+#endif  // LED_H_