No longer need a specific testmod for the LII test

We used to need a testmod that turned off GLC_TWO_WAY_COUPLING and
pointed to a compatible initial conditions file. However, this is no
longer needed, because:

- An LII test passes now even with GLC_TWO_WAY_COUPLING on (because
  ESCOMP#340 has been resolved)

- Even if that weren't the case, this compset now uses SGLC, which sets
  GLC_TWO_WAY_COUPLING=FALSE.

- The out-of-the-box initial conditions file is currently compatible
  with this configuration, so there's no need to point to an initial
  conditions file specifically for this test. (We could reintroduce a
  testmods later if we no longer have an out-of-the-box initial
  conditions file compatible with this test... though it may be better
  just to change the test so that it continues to have a compatible
  out-of-the-box initial conditions file, so that we don't need to
  maintain an initial conditions file just for this test.)

cime_config/SystemTests/lii.py

@@ -1,5 +1,4 @@
-"""
-Implementation of the CIME LII test.
+"""Implementation of the CIME LII test.
 
 This is a CLM specific test:
 Verifies that interpolation of initial conditions onto an identical
@@ -25,8 +24,9 @@
 space. Rename this to be similar to the name of the file pointed to in this
 test's user_nl_ctsm file, but with a new creation date.
 
-(3) Update this test's user_nl_ctsm file (in the appropriate testmods directory)
-to point to the new finidat file.
+(3) Update this test's user_nl_ctsm file (in the appropriate testmods directory, or in
+namelist_defaults if the test is using an out-of-the-box initial conditions file and it is
+acceptable to update that file) to point to the new finidat file.
 """
 
 from CIME.SystemTests.system_tests_compare_two import SystemTestsCompareTwo

cime_config/testdefs/testlist_clm.xml

@@ -1260,13 +1260,13 @@
       <option name="tput_tolerance">0.5</option>
     </options>
   </test>
-  <test name="LII_D_Ld3" grid="f19_g17_gl4" compset="I2000Clm50BgcCrop" testmods="clm/glcMEC_spunup_1way">
+  <test name="LII_D_Ld3" grid="f19_g17" compset="I2000Clm50BgcCrop" testmods="clm/default">
     <machines>
       <machine name="cheyenne" compiler="intel" category="aux_clm"/>
     </machines>
     <options>
       <option name="wallclock">00:20:00</option>
-      <option name="comment"  >Want to cover both glc_mec and crop in an LII test; this test covers both. Uses a year-2000 restart file so that the restart file has non-zero product pools, so that we exercise the gridcell-level code in init_interp. 2018-04-09: Now that SGLC tests use glc_mec, it would be more straightforward to run this test using a SGLC compset rather than a CISM compset that turns off two-way coupling; I was going to make that change now, but didn't want to risk it given the current time crunch, so let's make that change later.</option>
+      <option name="comment"  >Basic LII test, covering the standard range of subgrid heterogeneity - particularly, including crop. Uses a year-2000 restart file so that the restart file has non-zero product pools, so that we exercise the gridcell-level code in init_interp.</option>
     </options>
   </test>
   <test name="LII2FINIDATAREAS_D_P360x2_Ld1" grid="f09_g17" compset="I1850Clm50BgcCrop" testmods="clm/default">