The reconfiguration of PCM affected all PCM streams on the bus, but
this this should be done rather only for the target codec.

This patch does the following:
- introduce bitmap indicating the PCM device usages on a hda_bus
- refactor the PCM build functions
- fix __devinit prefix in some fucntions
- add a proper ifdef around HDA-reconfig-specific functions
Signed-off-by: Takashi Iwai <tiwai@suse.de>