[lldb] Also configure lldb_framework_dir in the lit.site.cfg.py

Configuring the variable in CMake isn't enought, because the build mode
can't be resolved until execution time, which requires the build mode to
be substituted by lit.

lldb/test/API/lit.site.cfg.py.in

@@ -59,6 +59,7 @@ try:
     config.dsymutil = config.dsymutil % lit_config.params
     config.filecheck = config.filecheck % lit_config.params
     config.yaml2obj = config.yaml2obj % lit_config.params
+    config.lldb_framework_dir = config.lldb_framework_dir % lit_config.params
     config.dotest_args_str = config.dotest_args_str % lit_config.params
 except KeyError as e:
     key, = e.args