[coreboot-gerrit] Change in coreboot[master]: soc/intel/tigerlake: Add empty _DSM for TCSS DMA devices

[Duncan Laurie (Code Review)]

Duncan Laurie has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/46641 )

Change subject: soc/intel/tigerlake: Add empty _DSM for TCSS DMA devices
......................................................................

Patch Set 1:

Hm actually I remember now why I removed the _DSM from the DMA device: it gets added by the SSDT for the retimer.

When testing this I was using the chromium tree which had not yet submitted the retimer patch so it was not creating the _DSM and s0ix wasn't working.  Once that patch landed it works.

For now we do not need this patch, but this needs to be handled cleaner somehow for both _DSD and _DSM since there can be only one defined per device and ideally we'd support the PCI _DSM properly.