ALSA: fireface: obsolete proc node to leave one node

In a series of Fireface, latter protocol has no way for drivers to
retrieve current clock configuration. On the other hand, this driver
has proc node for it.

This commit removes a proc node to dump both clock configuration
and synchronization status in one proc node.

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