portaudio: needs threads

Fixes:
http://autobuild.buildroot.org/results/ba2/ba2d3832cb6838b2126e0f7db223305eab579d59

[Peter: move above so sub options gets properly indented]
Signed-off-by: Gilles Talis <gilles.talis@gmail.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/portaudio/Config.in

@@ -1,5 +1,9 @@
+comment "portaudio needs a toolchain threads support"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS
+
 config BR2_PACKAGE_PORTAUDIO
 	bool "portaudio"
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help
 	  PortAudio is a free, cross-platform, open-source,
 	  audio I/O library.