libbluray: needs threads

Fixes:
http://autobuild.buildroot.net/results/2bc/2bc0ce057e54bd6ff7f9ade115c389648a2df2eb/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libbluray/Config.in

@@ -1,6 +1,10 @@
 config BR2_PACKAGE_LIBBLURAY
 	bool "libbluray"
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	help
 	  libbluray is a client library for accessing bluray disks.
 
 	  http://www.videolan.org/developers/libbluray.html
+
+comment "libbluray needs a toolchain w/ threads"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS