fix build on non-jit arches

Build on non-jit arch like s390 fails with

[translation:info] Translating target as defined by targetpypystandalone
[platform:msg] Setting platform to 'host' cc=None
Traceback (most recent call last):
  File "translate.py", line 322, in <module>
    main()
  File "translate.py", line 208, in main
    targetspec_dic, translateconfig, config, args = parse_options_and_load_target()
  File "translate.py", line 176, in parse_options_and_load_target
    targetspec_dic['handle_config'](config, translateconfig)
  File "targetpypystandalone.py", line 109, in handle_config
    raise Exception("You have to specify the --opt level.\n"
Exception: You have to specify the --opt level.
Try --opt=2 or --opt=jit, or equivalently -O2 or -Ojit .

pypy.spec

@@ -431,6 +431,8 @@ BuildPyPy \
   pypy \
 %if 0%{with_jit}
   "-Ojit" \
+%else
+  "-O2" \
 %endif
   %{nil}