sandbox: Add a simple sound driver

Add a sound driver for sandbox, which uses SDL.

Tested-by: Che-Liang Chiou <clchiou@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/include/asm/arch-sandbox/sound.h b/arch/sandbox/include/asm/arch-sandbox/sound.h
new file mode 100644
index 0000000..a32e8c8
--- /dev/null
+++ b/arch/sandbox/include/asm/arch-sandbox/sound.h
@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2013 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __SANDBOX_SOUND_H
+#define __SANDBOX_SOUND_H
+
+int sound_play(unsigned int msec, unsigned int frequency);
+
+int sound_init(const void *blob);
+
+#endif