5.11.0 displayport monitor neverending DPMS sleep bisected

Essentially a repeat of #1427 (closed) which affected 5.10.4 (and 5.11-rcX) whereby if a displayport monitor goes to sleep it never wakes up. Manually bisected (obvious from just looking at log history) to;

drm/amd/display: Revert "Fix EDID parsing after resume from suspend" https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/amd?id=1a10e5244778169a5a53a527d7830cf0438132a1

Which un-reverted the previous fix a month prior.

Revert "drm/amd/display: Fix memory leaks in S3 resume" https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/gpu/drm/amd?id=5efc1f4b454c6179d35e7b0c3eda0ad5763a00fc

So the drm_add_edid_modes() appears to be required.