pixiewps: add missing dependency on threads

Fixes:

  http://autobuild.buildroot.net/results/0c8d0eeb693ac29739845f489caffc2f9fa3b262/

Signed-off-by: Guillaume W. Bres <guillaume.bressaix@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/pixiewps/Config.in

@@ -1,7 +1,11 @@
 config BR2_PACKAGE_PIXIEWPS
 	bool "pixiewps"
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help
 	  Pixie WPS is a C based tool to audit networks against the so
 	  called "Pixie Dust" attack.
 
 	  https://github.com/wiire-a/pixiewps/wiki
+
+comment "pixiewps needs a toolchain w/ threads"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS