This commit updates the driver from version 6.6 to 7.1. In contrast
to the old driver the new one will now probe all available HDA devices
and will drive the first usable one, e.g.:
```
[init -> audio_drv] azalia0 [8086:160c]
[init -> audio_drv] :
[init -> audio_drv] azalia0: no supported codecs
[init -> audio_drv] azalia1 [8086:9ca0]
[init -> audio_drv] :
[init -> audio_drv] azalia1: codecs: Realtek ALC292
[init -> audio_drv] audio0 at azalia1
```
Fixes#4629.
