Revert "ALSA: memalloc: Convert x86 SG-buffer handling with non-contiguous type"

Revert "ALSA: memalloc: Convert x86 SG-buffer handling with non-contiguous type"

This reverts commit da1ae444527dd15c63de9f28b39aa20293b6ac63.

We've got a regression report showing that the audio got broken the
device over AMD IOMMU.  The conversion assumed the wrong pointer /
page mapping for the indirect mapping case, and we need to correct
this urgently, so let's revert it for now.

Fixes: da1ae444527d ("ALSA: memalloc: Convert x86 SG-buffer handling with non-contiguous type")
Reported-and-tested-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Link: https://lore.kernel.org/r/20211104180846.16340-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>