Make sure clean <COMPONENT> cleans up obj dir

When user runs "./case.build --clean atm" some files
(Srcfiles, Depends etc) still remain in the atm build
directory.

This change was missed (changes in cesm Makefile was not ported to
the acme Makefile) in ESMCI/cime#1140

Fixes #1474
[BFB]

config/acme/machines/Makefile

@@ -836,38 +836,38 @@ $(COMPLIB): $(OBJS)
 
 cleanatm:
 	$(RM) -f $(LIBROOT)/libatm.a
-	cd $(EXEROOT)/atm/obj;  $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/atm/obj
 
 cleancpl:
-	cd $(EXEROOT)/cpl/obj;  $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/cpl/obj
 
 cleanocn:
 	$(RM) -f $(LIBROOT)/libocn.a
-	cd $(EXEROOT)/ocn/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/ocn/obj
 
 cleanwav:
 	$(RM) -f $(LIBROOT)/libwav.a
-	cd $(EXEROOT)/wav/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/wav/obj
 
 cleanesp:
 	$(RM) -f $(LIBROOT)/libesp.a
-	cd $(EXEROOT)/esp/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/esp/obj
 
 cleanglc:
 	$(RM) -f $(LIBROOT)/libglc.a
 	$(RM) -fr $(EXEROOT)/glc
 
 cleanice:
 	$(RM) -f $(LIBROOT)/libice.a
-	cd $(EXEROOT)/ice/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/ice/obj
 
 cleanrof:
 	$(RM) -f $(LIBROOT)/librof.a
-	cd $(EXEROOT)/rof/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(EXEROOT)/rof/obj
 
 cleanlnd:
 	$(RM) -f $(LIBROOT)/liblnd.a
-	cd $(EXEROOT)/lnd/obj ; $(RM) -f *.o *.mod
+	$(RM) -fr $(LNDOBJDIR)
 
 cleancsmshare:
 	$(RM) -f $(CSMSHARELIB)