ALSA: i2c: constify snd_i2c_ops structures

The snd_i2c_ops structures are never modified, so declare them as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/include/sound/i2c.h b/include/sound/i2c.h
index d125ff8..835254d 100644
--- a/include/sound/i2c.h
+++ b/include/sound/i2c.h
@@ -66,7 +66,7 @@
 		struct snd_i2c_bit_ops *bit;
 		void *ops;
 	} hw_ops;		/* lowlevel operations */
-	struct snd_i2c_ops *ops;	/* midlevel operations */
+	const struct snd_i2c_ops *ops;	/* midlevel operations */
 
 	unsigned long private_value;
 	void *private_data;