In former commits, proxy structure gets members for cache of stream
formats. The cache allows to apply correct constraints and rules to
runtime of PCM substream. They allows userspace applications to change
current sampling transmission frequency.

This commit uses the cacher for the PCM constraints and rules.
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>