drm/amd/display: Send s0i2_rdy in stream_count == 0 optimization

drm/amd/display: Send s0i2_rdy in stream_count == 0 optimization

BugLink: https://bugs.launchpad.net/bugs/1956926
[ Upstream commit a07f8b9983543d465b50870ab4f845d4d710ed3f ]

[Why]
Otherwise SMU won't mark Display as idle when trying to perform s2idle.

[How]
Mark the bit in the dcn31 codepath, doesn't apply to older ASIC.

It needed to be split from phy refclk off to prevent entering s2idle
when PSR was engaged but driver was not ready.

Fixes: 118a33151658 ("drm/amd/display: Add DCN3.1 clock manager support")
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Eric Yang <Eric.Yang2@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <p.pisati@gmail.com>