[ALSA] Add write support to snd-page-alloc proc file

Documentation,Memalloc module,RME HDSP driver,RME9652 driver
Add the write support to snd-page-alloc proc file for buffer pre-allocation.
Removed the pre-allocation codes via module options.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
4 files changed