Revert "drm/amd/display: fix dpms_off issue when disabling bios mode"

This reverts commit 5aa66375.

This causes a blank screen on boot on an Asus G513QY / 6800M laptop.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2259


Cc: Aric Cyr <Aric.Cyr@amd.com>
Cc: Tom Chung <chiahsuan.chung@amd.com>
Cc: Zhongwei Zhang <Zhongwei.Zhang@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Tested-by: Mike Lothian <mike@fireburn.co.uk>
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>