putty: needs wchar support

putty uses mbstate_t, which is a wchar related definition, so wchar
support is needed in the toolchain.

Fixes:

  http://autobuild.buildroot.net/results/0e3f4306513b79306d43338eced890205632c395/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/putty/Config.in

@@ -1,9 +1,14 @@
 config BR2_PACKAGE_PUTTY
 	bool "putty"
 	depends on BR2_USE_MMU # fork()
+	depends on BR2_USE_WCHAR
 	help
 	  PuTTY is a free SSH and Telnet client. Without GTK2 activated,
 	  only the commandline tools plink, pscp, psftp, and puttygen are
 	  built; enable GTK2 for the graphical client.
 
 	  http://www.chiark.greenend.org.uk/~sgtatham/putty/
+
+comment "putty needs a toolchain w/ wchar"
+	depends on BR2_USE_MMU
+	depends on !BR2_USE_WCHAR