ASoC: Intel: sst: Switch to standard device pages

ASoC Atom SST driver is using the continuous RAM pages with GFP_DMA
flag for its PCM buffer, but this should work fine with the standard
DMA pages.  As a part of cleanup work, this patch replaces the buffer
allocation to the standard device pages with SNDRV_DMA_TYPE_DEV.

Link: https://lore.kernel.org/r/20220823115740.14123-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>