drm/amd/display: Revert FEC check in validation

why and how:
causes failure on install on certain machines

Reviewed-by: George Shen <George.Shen@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Martin Leung <Martin.Leung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>