Fix which ptl_mulltlayer_enabled_flag is used
When sps_ptl_dpb_hrd_params_present_flag=0 (MultiLayer OLS) ptl_mulltlayer_enabled_flag is not signaled in SPS.
In this case decoder uses ptl_mulltlayer_enabled_flag from corresponding VPS PTL.
When sps_ptl_dpb_hrd_params_present_flag=0 (MultiLayer OLS) ptl_mulltlayer_enabled_flag is not signaled in SPS.
In this case decoder uses ptl_mulltlayer_enabled_flag from corresponding VPS PTL.