ALSA: x86: simplify with sync_stop PCM ops

The reset procedure in had_do_reset() is exactly for the recently
introduced PCM sync_stop ops.  Replace the call with the new ops and
clean up the unnecessary code and flags.

Link: https://lore.kernel.org/r/20210712091915.28067-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>