CMakePM: Use the right type for the few kit CMake variables

Use FILEPATH for CMAKE_C|CXX_COMPILER variables, and PATH for directory
variables like CMAKE_PREFIX_PATH.

Task-number: QTCREATORBUG-27005
Change-Id: I906de43ab97d2dbad0374469c4576d901d2f6339
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/cmakeprojectmanager/cmakeconfigitem.cpp

@@ -51,6 +51,10 @@ CMakeConfigItem::CMakeConfigItem(const QByteArray &k, Type t,
     key(k), type(t), value(v), documentation(d), values(s)
 { }
 
+CMakeConfigItem::CMakeConfigItem(const QByteArray &k, Type t, const QByteArray &v) :
+    key(k), type(t), value(v)
+{ }
+
 CMakeConfigItem::CMakeConfigItem(const QByteArray &k, const QByteArray &v) :
     key(k), value(v)
 { }