wavemon: depends on a toolchain with NPTL

The software uses pthread_mutexattr_setrobust which isn't
available in uClibc-ng Linuxthreads support.

Fixes:
http://autobuild.buildroot.net/results/d81b199c74cb4251f0b0eb975f66cb5016eb464c/

Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/wavemon/Config.in

@@ -1,6 +1,6 @@
 config BR2_PACKAGE_WAVEMON
 	bool "wavemon"
-	depends on BR2_TOOLCHAIN_HAS_THREADS
+	depends on BR2_TOOLCHAIN_HAS_THREADS_NPTL
 	select BR2_PACKAGE_NCURSES
 	select BR2_PACKAGE_LIBNL
 	help
@@ -14,5 +14,5 @@ config BR2_PACKAGE_WAVEMON
 
 	  https://github.com/uoaerg/wavemon
 
-comment "wavemon needs a toolchain w/ threads"
-	depends on !BR2_TOOLCHAIN_HAS_THREADS
+comment "wavemon needs a toolchain w/ NPTL"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS_NPTL