ALSA: hda: Update documentation for aliasing via the model option

The previous patch allowed user to specify the aliasing of SSID via
model option for applying a quirk.  Update the documentation
accordingly.

Link: https://lore.kernel.org/r/20210823073722.14873-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Documentation/sound/alsa-configuration.rst

@@ -1059,6 +1059,12 @@ The model name ``generic`` is treated as a special case.  When this
 model is given, the driver uses the generic codec parser without
 "codec-patch".  It's sometimes good for testing and debugging.
 
+The model option can be used also for aliasing to another PCI or codec
+SSID.  When it's passed in the form of ``model=XXXX:YYYY`` where XXXX
+and YYYY are the sub-vendor and sub-device IDs in hex numbers,
+respectively, the driver will refer to that SSID as a reference to the
+quirk table.
+
 If the default configuration doesn't work and one of the above
 matches with your device, report it together with alsa-info.sh
 output (with ``--no-upload`` option) to kernel bugzilla or alsa-devel

Documentation/sound/hd-audio/notes.rst

@@ -215,6 +215,17 @@ There are a few special model option values:
 * when ``generic`` is passed, the codec-specific parser is skipped and
   only the generic parser is used.
 
+A new style for the model option that was introduced since 5.15 kernel
+is to pass the PCI or codec SSID in the form of ``model=XXXX:YYYY``
+where XXXX and YYYY are the sub-vendor and sub-device IDs in hex
+numbers, respectively.  This is a kind of aliasing to another device;
+when this form is given, the driver will refer to that SSID as a
+reference to the quirk table.  It'd be useful especially when the
+target quirk isn't listed in the model table.  For example, passing
+model=103c:8862 will apply the quirk for HP ProBook 445 G8 (which
+isn't found in the model table as of writing) as long as the device is
+handled equivalently by the same driver.
+
 
 Speaker and Headphone Output
 ----------------------------