Break out the allocation of pages for DMA and PCM buffers to ops in
the chip structure.  This is done to allow for architecture specific
work-arounds to be added.  Currently mark_pages_wc is used by
hda_intel.  This avoids needing to move that x86-specific code to a
common area shared with hda platform drivers.
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>