ALSA: hda: Allow the default preallocation for x86 again

Since there are a few corner cases where the S/G buffer allocation
isn't performed (e.g. depending on IOMMU implementations), it'd be
better to allow the default buffer preallocation size for x86, too.

The default for x86 is still kept to 0, as it should work in most
cases.

Link: https://patch.msgid.link/20240907084129.28802-1-tiwai@suse.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>