ALSA: Move some headers to local directories from include/sound

This is a bit clean up of public sound header directory.
Some header files in include/sound aren't really necessary to be
located there but can be moved to their local directories gracefully.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/trident/trident_main.c

@@ -41,7 +41,7 @@
 #include <sound/info.h>
 #include <sound/control.h>
 #include <sound/tlv.h>
-#include <sound/trident.h>
+#include "trident.h"
 #include <sound/asoundef.h>
 
 #include <asm/io.h>