drm/amd/display: Ignore scalar validation failure if pipe is phantom

[Why]
There are some pipe scaler validation failure when the pipe is phantom
and causes crash in DML validation. Since, scalar parameters are not
as important in phantom pipe and we require this plane to do successful
MCLK switches, the failure condition can be ignored.

[How]
Ignore scalar validation failure if the pipe validation is marked as
phantom pipe.

Cc: stable@vger.kernel.org # 6.11+
Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Chris Park <chris.park@amd.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>