drm/amd/display: fix the ability to use lower resolution modes on eDP

commit 2de19022 upstream.

On eDP we can receive invalid modes from dm_update_crtc_state() for
entirely new streams for which drm_mode_set_crtcinfo() shouldn't be
called on. So, instead of calling drm_mode_set_crtcinfo() from within
create_stream_for_sink() we can instead call it from
amdgpu_dm_connector_mode_valid(). Since, we are guaranteed to only call
drm_mode_set_crtcinfo() for valid modes from that function (invalid
modes are rejected by that callback) and that is the only user
of create_validate_stream_for_sink() that we need to call
drm_mode_set_crtcinfo() for (as before commit cb841d27
("drm/amd/display: Always pass connector_state to stream validation"),
that is the only place where create_validate_stream_for_sink()'s
dm_state was NULL).

Cc: stable@vger.kernel.org
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2693
Fixes: cb841d27

 ("drm/amd/display: Always pass connector_state to stream validation")
Tested-by: Mark Broadworth <mark.broadworth@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>