ALSA: control: Fix incompatible protocol error

The recent change to bump the ALSA control API protocol version from
2.0.7 to 2.1.0 caused a regression on user-space; while the user-space
expects both the major and the minor versions to be identical with the
supported numbers, we changed the minor number from 0 to 1.

For recovering from the incompatibility, this patch changes the
protocol version again to 2.0.8, which is compatible, but yet higher
than the original number 2.0.7, indicating that the protocol change.

Fixes: bd3eb4e8 ("ALSA: ctl: bump protocol version up to v2.1.0")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/r/s5h1rsr769i.wl-tiwai@suse.de


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