Merge branch 'wlin/atm/calipsofix-mgflx' (PR #1333)

Fixes for CALIPSO simulator and MG precipitation fluxes

This fixes CALIPSO simulator that shows abnormal spatial distribution.
The root cause is that the pressure cutoff for MG calculation leads to
precipitation flux arrays containing undefined values above the cut off
level. It was not an issue with original L30 configuration.

Fixes for precipitation flux calculations for MG2 microphysics are also
included, but not to include liquid and condensate fluxes to the MG
precipitation fluxes to avoid potential complication in COSP's
lidar/radar simulators.

modified: components/cam/src/physics/cam/cospsimulator_intr.F90
modified: components/cam/src/physics/cam/micro_mg1_0.F90
modified: components/cam/src/physics/cam/micro_mg2_0.F90
modified: components/cam/src/physics/cam/micro_mg_cam.F90

[BFB]

* wlin/atm/calipsofix-mgflx:
  Modify precipitation flux calculation to avoid potential issue in COSP
  Fixes for CALIPSO simulator and MG precipitation fluxes