Merge branch 'xylar/mpas-framework/add-openmp-to-gnu-nersc' into next…

… (PR #4910)

MPAS Standalone: Add OpenMP support to gnu-nersc

For some reason this was omitted when OpenMP support was added 8 years
ago. This has become a problem in compass because we switched to building
with OpenMP on by default: MPAS-Dev/compass#364
Does not impact E3SM builds.

[BFB]

components/mpas-framework/Makefile

@@ -445,11 +445,14 @@ gnu-nersc:
 	"CFLAGS_DEBUG = -g -m64" \
 	"CXXFLAGS_DEBUG = -g -m64" \
 	"LDFLAGS_DEBUG = -g -m64" \
+	"FFLAGS_OMP = -fopenmp" \
+	"CFLAGS_OMP = -fopenmp" \
 	"BUILD_TARGET = $(@)" \
 	"CORE = $(CORE)" \
 	"DEBUG = $(DEBUG)" \
 	"SERIAL = $(SERIAL)" \
 	"USE_PAPI = $(USE_PAPI)" \
+	"OPENMP = $(OPENMP)" \
 	"USE_SHTNS = $(USE_SHTNS)" \
 	"CPPFLAGS = $(MODEL_FORMULATION) -D_MPI $(FILE_OFFSET) $(ZOLTAN_DEFINE)" )