Merge branch 'bishtgautam/lnd/topo-output' (PR #3448)

Adds output of topography in land history file

The missing call to output topography in clm2.h0 files is added

Fixes #3447
[non-BFB]

components/clm/src/main/histFileMod.F90

@@ -2667,6 +2667,7 @@ subroutine htape_timeconst(t, mode)
           call ncd_io(varname='lon', data=ldomain%lonc, dim1name=grlnd, ncid=nfid(t), flag='write')
           call ncd_io(varname='lat', data=ldomain%latc, dim1name=grlnd, ncid=nfid(t), flag='write')
        end if
+       call ncd_io(varname='topo'    , data=ldomain%topo, dim1name=grlnd, ncid=nfid(t), flag='write')
        call ncd_io(varname='area'    , data=ldomain%area, dim1name=grlnd, ncid=nfid(t), flag='write')
        call ncd_io(varname='landfrac', data=ldomain%frac, dim1name=grlnd, ncid=nfid(t), flag='write')
        call ncd_io(varname='landmask', data=ldomain%mask, dim1name=grlnd, ncid=nfid(t), flag='write')