decoder: H265: Enable cu_qp_delta_enabled_flag when ROI
If ROI is enabled, the CUs within the ROI region may have different QP from the other part of the picture. This needs us to enable the cu_qp_delta_enabled_flag even in the CQP mode.
If ROI is enabled, the CUs within the ROI region may have different QP from the other part of the picture. This needs us to enable the cu_qp_delta_enabled_flag even in the CQP mode.