drm/amd/display: Always wait for update lock status

Remove code that would skip wait for lock status for Diags
FPGA case

Reviewed-by: Laktyushkin Dmytro <dmytro.laktyushkin@amd.com>
Acked-by: Solomon Chiu <solomon.chiu@amd.com>
Signed-off-by: Eric Bernstein <eric.bernstein@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>