sh: ecovec: add sample amixer settings

FSI - DA7210 needs amixer settings to use it.
This patch adds quick setting guide

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/boards/mach-ecovec24/setup.c

@@ -70,6 +70,16 @@
  *                                  OFF-ON : MMC
  */
 
+/*
+ * FSI - DA7210
+ *
+ * it needs amixer settings for playing
+ *
+ * amixer set 'HeadPhone' 80
+ * amixer set 'Out Mixer Left DAC Left' on
+ * amixer set 'Out Mixer Right DAC Right' on
+ */
+
 /* Heartbeat */
 static unsigned char led_pos[] = { 0, 1, 2, 3 };