Genex: Add generator expressions $<DEVICE_LINK> and $<HOST_LINK>

These generator expressions can only be used in link options properties.
These expressions return the arguments respectively for device and host link
step, otherwise return an empty string.

Source/cmStringAlgorithms.h

@@ -87,7 +87,7 @@ void cmExpandLists(InputIt first, InputIt last,
                    std::vector<std::string>& argsOut)
 {
   for (; first != last; ++first) {
-    ExpandList(*first, argsOut);
+    cmExpandList(*first, argsOut);
   }
 }