if unused in that configuration mixer at NID 15 is muted. Probably CODEC
incorrectly reports its internal connections. Hide that muter from the
driver to avoid muting and make built-in speaker work.
There are several different CODECs sharing this ID and I have not enough
information about them and the bug to implement more universal solution.
Tested by: Big Yuuta <init.py@gmail.com>
MFC after: 2 weeks