Revert "drm/amd: Keep display off while going into S4"

Revert "drm/amd: Keep display off while going into S4"

commit 68bfdc8dc0a1a ("drm/amd: Keep display off while going into S4")
attempted to keep displays off during the S4 sequence by not resuming
display IP.  This however leads to hangs because DRM clients such as the
console can try to access registers and cause a hang.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4155
Fixes: 68bfdc8dc0a1a ("drm/amd: Keep display off while going into S4")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20250522141328.115095-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>