ALSA: pcm: move fixup of info flag after selecting single parameters

When drivers register no flags about information of PCM hardware, ALSA
PCM core fixups it roughly. Currently, this operation places in a
function snd_pcm_hw_refine(). It can be moved to a function
fixup_unreferenced_params() because it doesn't affects operations
between these two functions.

This idea is better to bundle codes with similar purposes and this commit
achieves it.

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