Only build cvs and libxml2 if WCHAR is enabled

package/cvs/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_CVS
 	bool "cvs"
 	default n
+	depends on BR2_USE_WCHAR
 	select BR2_PACKAGE_NCURSES
 	help
 	  Concurrent Versions System - source code revision control tools.

package/libxml2/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_LIBXML2
 	bool "libxml2"
 	default n
+	depends on BR2_USE_WCHAR
 	help
 	  XML C Parser
 	  Requires WCHAR