Update -tp option for recent nvfortran on x86_64

Author: martin-frbg

Makefile.system

@@ -1122,8 +1122,12 @@ FCOMMON_OPT += -i8
 endif
 endif
 ifeq ($(ARCH), x86_64)
+ifneq ($(NEWPGI2),1)
 FCOMMON_OPT += -tp p7-64
 else
+FCOMMON_OPT += -tp px
+endif
+else
 ifeq ($(ARCH), power)
 ifeq ($(CORE), POWER6)
 $(warning NVIDIA HPC compilers do not support POWER6.)