ALSA: hda - Consolidate add_in_jack_modes and add_out_jack_modes hints

There is no big merit to distinguish these two hints.  Instead, just
have a single flag, add_jack_modes, for creating the jack mode enum
ctls for both I/O directions.

The hint string parser code is left and translated as add_jack_modes
just for keeping compatibility.

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

Documentation/sound/alsa/HD-Audio.txt

@@ -461,10 +461,9 @@ The generic parser supports the following hints:
   the corresponding mixer control, if available
 - add_stereo_mix_input (bool): add the stereo mix (analog-loopback
   mix) to the input mux if available
-- add_out_jack_modes (bool): add "xxx Jack Mode" enum controls to each
-  output jack for allowing to change the headphone amp capability
-- add_in_jack_modes (bool): add "xxx Jack Mode" enum controls to each
-  input jack for allowing to change the mic bias vref
+- add_jack_modes (bool): add "xxx Jack Mode" enum controls to each
+  I/O jack for allowing to change the headphone amp and mic bias VREF
+  capabilities
 - power_down_unused (bool): power down the unused widgets
 - add_hp_mic (bool): add the headphone to capture source if possible
 - hp_mic_detect (bool): enable/disable the hp/mic shared input for a