docn-multilev is not reading in ocn input correctly

[mvertens]

In the aux_cdeps test ERS_D_Ly4.f09_tn14.1850_SATM_SLND_SICE_DOCN%MULTILEV-CPLHIST_SROF_SGLC_SWAV.betzy_gnu.docn-multilev_cplhist - all of the ocnImp_So_t_depthNN are spval.