ALSA: hda: Unexport some local helper functions

snd_hdac_bus_queue_event() and snd_hdac_bus_exec_verb() are used only
internally in HD-audio core.  Let's drop the exports and move the
declarations into local.h.

Link: https://lore.kernel.org/r/20200516062854.22141-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/hda/hdac_controller.c

@@ -9,6 +9,7 @@
 #include <sound/core.h>
 #include <sound/hdaudio.h>
 #include <sound/hda_register.h>
+#include "local.h"
 
 /* clear CORB read pointer properly */
 static void azx_clear_corbrp(struct hdac_bus *bus)