audio: add soundhw deprecation notice

Signed-off-by: Gerd Hoffmann <[email protected]>
Message-id: [email protected]

Author: kraxel

docs/system/deprecated.rst

@@ -82,6 +82,15 @@ should specify an ``audiodev=`` property.  Additionally, when using
 vnc, you should specify an ``audiodev=`` propery if you plan to
 transmit audio through the VNC protocol.
 
+Creating sound card devices using ``-soundhw`` (since 5.1)
+''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+Sound card devices should be created using ``-device`` instead.  The
+names are the same for most devices.  The exceptions are ``hda`` which
+needs two devices (``-device intel-hda -device hda-duplex``) and
+``pcspk`` which can be activated using ``-machine
+pcspk-audiodev=<name>``.
+
 ``-mon ...,control=readline,pretty=on|off`` (since 4.1)
 '''''''''''''''''''''''''''''''''''''''''''''''''''''''