poppler: needs thread support

Fix:
http://autobuild.buildroot.net/results/daa/daa18f112ddd08644b4149025899cea2b511a9da/

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/poppler/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_POPPLER
 	bool "poppler"
 	depends on BR2_INSTALL_LIBSTDCPP
+	depends on BR2_TOOLCHAIN_HAS_THREADS
 	select BR2_PACKAGE_FONTCONFIG
 	select BR2_PACKAGE_XLIB_LIBX11 if BR2_PACKAGE_XORG7
 	select BR2_PACKAGE_XLIB_LIBXEXT if BR2_PACKAGE_XORG7
@@ -9,5 +10,5 @@ config BR2_PACKAGE_POPPLER
 
 	   http://poppler.freedesktop.org/
 
-comment "poppler requires a toolchain with C++ support enabled"
-	depends on !BR2_INSTALL_LIBSTDCPP
+comment "poppler requires a toolchain with C++ and thread support enabled"
+	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_TOOLCHAIN_HAS_THREADS