ALSA: dice: Split PCM functionality into a file

This commit adds a file and move some codes related to PCM functionality.

Currently PCM playback is supported. PCM capture will be supported in followed
commits.

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

diff --cc sound/firewire/dice/Makefile
Simple merge

diff --cc sound/firewire/dice/dice-pcm.c
Simple merge

diff --cc sound/firewire/dice/dice-stream.c
Simple merge

diff --cc sound/firewire/dice/dice.c
Simple merge

diff --cc sound/firewire/dice/dice.h
Simple merge