Revert "drm/amdgpu/display: set vblank_disable_immediate for DC"

commit a775e4e4 upstream.

This reverts commit 92020e81

.

This causes stuttering and timeouts with DMCUB for some users
so revert it until we understand why and safely enable it
to save power.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1887
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>