clean up GNUmakefile; change compile defaults (no OMP, no LLG, no GPU…

…CLOCK)

GNUmakefile

@@ -1,6 +1,4 @@
 AMREX_HOME  ?= ../amrex
-PICSAR_HOME ?= ../picsar
-OPENBC_HOME ?= ../openbc_poisson
 
 DEBUG = FALSE
 #DEBUG	= TRUE
@@ -24,12 +22,13 @@ TINY_PROFILE   = TRUE
 #COMM_PROFILE  = TRUE
 #TRACE_PROFILE = TRUE
 
-USE_OMP   = TRUE
+USE_MPI   = TRUE
+USE_OMP   = FALSE
 USE_GPU   = FALSE
 
 EBASE     = main
 
-USE_GPUCLOCK = TRUE
+USE_GPUCLOCK = FALSE
 USE_PYTHON_MAIN = FALSE
 
 USE_SENSEI_INSITU = FALSE
@@ -41,7 +40,7 @@ WarpxBinDir = Bin
 USE_PSATD = FALSE
 USE_PSATD_PICSAR = FALSE
 USE_RZ = FALSE
-USE_LLG = TRUE
+USE_LLG = FALSE
 
 USE_EB = FALSE