ALSA: hda - Clarify CONFIG_SND_HDA_RECONFIG usages

Since the recent rewrite of HD-audio infrastructure,
CONFIG_SND_HDA_RECONFIG has a slightly different meaning.  In the
earlier versions, it implicitly assumed only the usage via hwdep sysfs
entries.  Meanwhile, in the recent version, this option is meant to
enable the reconfig code in HD-audio driver, which may be used by the
patch loader without hwdep interface.

This patch tries to clarify the usage pattern a bit better, hopefully
avoid the further confusion.

Reported-by: Jochen Henneberg <jh@henneberg-systemdesign.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/hda/Kconfig

@@ -50,9 +50,13 @@ config SND_HDA_RECONFIG
 	bool "Allow dynamic codec reconfiguration"
 	help
 	  Say Y here to enable the HD-audio codec re-configuration feature.
-	  This adds the sysfs interfaces to allow user to clear the whole
-	  codec configuration, change the codec setup, add extra verbs,
-	  and re-configure the codec dynamically.
+	  It allows user to clear the whole codec configuration, change the
+	  codec setup, add extra verbs, and re-configure the codec dynamically.
+
+	  Note that this item alone doesn't provide the sysfs interface, but
+	  enables the feature just for the patch loader below.
+	  If you need the traditional sysfs entries for the manual interaction,
+	  turn on CONFIG_SND_HDA_HWDEP as well.
 
 config SND_HDA_INPUT_BEEP
 	bool "Support digital beep via input layer"