package/bird: BFD needs NPTL

Fixes:
 - http://autobuild.buildroot.org/results/ab9ab2cca2c191ae9a8f0ecb2aa2536a3f020301

uClibc linuxthreads does not provide pthread_spin_lock().

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/bird/Config.in

@@ -29,12 +29,12 @@ config BR2_PACKAGE_BIRD_BABEL
 
 config BR2_PACKAGE_BIRD_BFD
 	bool "bfd"
-	depends on BR2_TOOLCHAIN_HAS_THREADS
+	depends on BR2_TOOLCHAIN_HAS_THREADS_NPTL
 	help
 	  Enable BFD protocol.
 
-comment "BFD protocol needs a toolchain w/ threads"
-	depends on !BR2_TOOLCHAIN_HAS_THREADS
+comment "BFD protocol needs a toolchain w/ NPTL"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS_NPTL
 
 config BR2_PACKAGE_BIRD_BGP
 	bool "bgp"