This reverts commit 3ad796cbc3 ("ALSA: pcm: Use SG-buffer only when
direct DMA is available") also the modification commit 467fd0e82b
("ALSA: pcm: Fix build error on m68k and others").
Poking the DMA internal helper is a layer violation, so we should
avoid that. Meanwhile the actual bug has been addressed by the
Kconfig fix in commit dbed452a07 ("dma-pool: decouple DMA_REMAP from
DMA_COHERENT_POOL"), so we can live without this hack.
Link: https://lore.kernel.org/r/20200717064130.22957-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>