Add module to read ozone_coupling_nl

[billsacks]

This will work together with ESCOMP/CMEPS#212. However, this can safely be brought in prior to that PR, because this code is not yet invoked from anywhere.

I have run SMS_D_Ln1_Vnuopc.f10_f10_mg37.I2000Clm50BgcCropQianRs.cheyenne_intel and SMS_D_Ln1_Vnuopc.f10_f10_mg37.F2000climo.cheyenne_intel with hashes listed in ESCOMP/CMEPS#212 along with these CTSM diffs:

diff --git a/src/cpl/nuopc/lnd_import_export.F90 b/src/cpl/nuopc/lnd_import_export.F90
index f4e0759a..f6e5dbb8 100644
--- a/src/cpl/nuopc/lnd_import_export.F90
+++ b/src/cpl/nuopc/lnd_import_export.F90
@@ -153,6 +153,7 @@ contains
 
     use shr_carma_mod     , only : shr_carma_readnl
     use shr_ndep_mod      , only : shr_ndep_readnl
+    use shr_ozone_coupling_mod, only : shr_ozone_coupling_readnl
     use shr_fire_emis_mod , only : shr_fire_emis_readnl
     use clm_varctl        , only : ndep_from_cpl
 
@@ -172,6 +173,7 @@ contains
     integer           :: n, num
     logical           :: send_co2_to_atm = .false.
     logical           :: recv_co2_fr_atm = .false.
+    integer           :: atm_ozone_frequency_val
 
     ! BUG(wjs, 2020-12-22, ESCOMP/CTSM#1237) force_send_to_atm should be read from the
     ! namelist rather than being hard-coded to true.
@@ -353,6 +355,9 @@ contains
     ! from - atm dry dust deposition frluxes (4 sizes)
     call fldlist_add(fldsToLnd_num, fldsToLnd, Faxa_dstdry, ungridded_lbound=1, ungridded_ubound=4)
 
+    call shr_ozone_coupling_readnl("drv_flds_in", atm_ozone_frequency_val)
+    write(iulog,*) 'atm_ozone_frequency_val = ', atm_ozone_frequency_val
+
     ! from atm - nitrogen deposition
     call shr_ndep_readnl("drv_flds_in", ndep_nflds)
     if (ndep_nflds > 0) then

I have confirmed that the values are set correctly in these different configurations, along with running the F compset with the following in user_nl_cam:

atm_ozone_frequency = 'instantaneous'

[billsacks]

We may change monthly_interpolated to some other value - see @fvitt 's comment in ESCOMP/CAM#404 (comment). Once that conversation is resolved, I'll make the necessary change here, and then this PR can be merged assuming that @mvertens approves.

[billsacks]

Okay, I have made the desired change in name. However, I'm still waiting to see if we may need to add another namelist flag describing something about the spatial resolution of the ozone field (See the discussion starting with ESCOMP/CAM#404 (comment))

[billsacks]

Okay, the relevant conversation was resolved in ESCOMP/CAM#404, so I'm merging.