pcm: hw: Call USER_PVERSION ioctl at open

pcm: hw: Call USER_PVERSION ioctl at open

Up from the new PCM protocol 2.0.14, user-space can inform the
protocol version it supports to kernel, so that the kernel may switch
its behavior depending on it.  Add this ioctl call in the PCM hw
plugin at opening.

The patch contains also the addition of SNDRV_PCM_INFO_SYNC_APPLPTR
carried from the upstream kernel commit 42f945970af9 ("ALSA: pcm: Add
the explicit appl_ptr sync support"), as well as the trivial change
(an addition of comma) to sync with the kernel asound.h.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Tested-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>