ALSA: oxfw: set packet parameter according to current configuration

After a call of pcm.hw_params, the state of target device is expected
for applications. This commit retrieves the state and start packet
streaming.

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