Revert "ALSA: hda: Conditionally use snooping for AMD HDMI"

Revert "ALSA: hda: Conditionally use snooping for AMD HDMI"

This reverts commit 478689b5990deb626a0b3f1ebf165979914d6be4.

The fix seems leading to regressions for other systems.
Also, the way to check the presence of IOMMU via get_dma_ops() isn't
reliable and it's no longer applicable for 6.12.  After all, it's no
right fix, so let's revert it at first.

To be noted, the PCM buffer allocation has been changed to try the
continuous pages at first since 6.12, so the problem could be already
addressed without this hackish workaround.

Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Closes: https://lore.kernel.org/ZvgCdYfKgwHpJXGE@eldamar.lan
Link: https://patch.msgid.link/20241002155948.4859-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>