drm/amd/display: Don't use DRM_ERROR() for DTM add topology

[Why]
Previously we were only calling add_topology when hdcp was being enabled.
Now we call add_topology by default so the ERROR messages are printed if
the firmware is not loaded.

This error message is not relevant for normal display functionality so
no need to print a ERROR message.

[How]
Change DRM_ERROR to DRM_INFO

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>