ASoC: Remove 'const' from the device_node pointers

As Russell King's explained it, there should not be pointers to
struct device_node:

"struct device_node is a ref-counted structure.  That means if you
 store a reference to it, you should "get" it, and you should "put"
 it once you've done.  The act of "put"ing the pointed-to structure
 involves writing to that structure, so it is totally unappropriate
 to store a device_node structure as a const pointer.  It forces you
 to have to cast it back to a non-const pointer at various points
 in time to use various OF function calls."

[This isn't quite the application here, we're not geting or putting the
pointer though we did add some other users who call non-const OF
functions -- broonie]
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc.h

@@ -881,7 +881,7 @@ struct snd_soc_platform_driver {
 
 struct snd_soc_dai_link_component {
 	const char *name;
-	const struct device_node *of_node;
+	struct device_node *of_node;
 	const char *dai_name;
 };
 
@@ -983,7 +983,7 @@ struct snd_soc_codec_conf {
 	 * DT/OF node, but not both.
 	 */
 	const char *dev_name;
-	const struct device_node *of_node;
+	struct device_node *of_node;
 
 	/*
 	 * optional map of kcontrol, widget and path name prefixes that are
@@ -1000,7 +1000,7 @@ struct snd_soc_aux_dev {
 	 * DT/OF node, but not both.
 	 */
 	const char *codec_name;
-	const struct device_node *codec_of_node;
+	struct device_node *codec_of_node;
 
 	/* codec/machine specific init - e.g. add machine controls */
 	int (*init)(struct snd_soc_component *component);