sed: show it in config menu when toolchain lacks wchar

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/sed/Config.in

@@ -6,4 +6,5 @@ config BR2_PACKAGE_SED
 
 	  http://sed.sourceforge.net/
 
-	  Most people will answer Y.
+comment "sed requires a toolchain with WCHAR support"
+	depends on !BR2_USE_WCHAR