dice: obsolete atomic_t for reference counter

Dice driver uses atomic_t for reference counter of substreams (MIDI/PCM)
and mutex for operation of streams.

Originally, I added atomic_t to enclose larger critical sections inner
functions of -stream.c. But it's cumbersome that this driver uses some
mutual exclusive primitives for streams.

This commit obsoletes atomic_t and use mutex only.
oxfw: obsolete atomic_t for reference counter

OXFW driver uses atomic_t for reference counter of substreams (MIDI/PCM)
and mutex for operation of streams.

Originally, I added atomic_t to enclose larger critical sections inner
functions of -stream.c. But it's cumbersome that this driver uses some
mutual exclusive primitives for streams.

This commit obsoletes atomic_t and use mutex only.
sync to patch candidates.

[alsa-devel] [PATCH 00/30 v3] ALSA: Enhancement for existed FireWire drivers
http://mailman.alsa-project.org/pipermail/alsa-devel/2014-November/084791.html