ASoC: au1x: Constify platform_device_id

The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/au1x/db1200.c

@@ -21,7 +21,7 @@
 #include "../codecs/wm8731.h"
 #include "psc.h"
 
-static struct platform_device_id db1200_pids[] = {
+static const struct platform_device_id db1200_pids[] = {
 	{
 		.name		= "db1200-ac97",
 		.driver_data	= 0,