ALSA: Merge memalloc code into snd-pcm module

Instead of keeping a separate snd-page-alloc module, merge into the
core snd-pcm module, as we don't need to keep it as an individual
module due to the drop of page reservation.

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

diff --cc sound/core/Makefile
Simple merge

diff --cc sound/core/memalloc.c
Simple merge