package/botan: fix build without NPTL

botan unconditionally uses pthread_setname_np since bump to version
3.2.0 in commit 2f8feb66204ff661e9fd5f508e2dfd1ebc0f2813 and
https://github.com/randombit/botan/commit/313e439c786d68bcf374b2cb0edfe3ffd891db94
resulting in the following build failure:

src/lib/utils/os_utils.cpp:625:22: error: 'pthread_setname_np' was not declared in this scope
  625 |    static_cast<void>(pthread_setname_np(thread.native_handle(), name.c_str()));
      |                      ^~~~~~~~~~~~~~~~~~

So only enable threads if NPTL is available

Fixes: 2f8feb66204ff661e9fd5f508e2dfd1ebc0f2813
 - http://autobuild.buildroot.org/results/03677de6270ff5de61fff2a76e5cd723aa34e64e

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

package/botan/Config.in

@@ -15,7 +15,6 @@ config BR2_PACKAGE_BOTAN
 	bool "botan"
 	depends on BR2_INSTALL_LIBSTDCPP
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_10 # C++20
-	depends on BR2_TOOLCHAIN_HAS_THREADS
 	depends on BR2_PACKAGE_BOTAN_ARCH_SUPPORTS
 	select BR2_PACKAGE_BOOST_FILESYSTEM if BR2_PACKAGE_BOOST && BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS
 	select BR2_PACKAGE_BOOST_SYSTEM if BR2_PACKAGE_BOOST && BR2_TOOLCHAIN_SUPPORTS_ALWAYS_LOCKFREE_ATOMIC_INTS
@@ -24,7 +23,7 @@ config BR2_PACKAGE_BOTAN
 
 	  http://botan.randombit.net
 
-comment "botan needs a toolchain w/ C++, threads, gcc >= 10"
-	depends on !BR2_TOOLCHAIN_HAS_THREADS || !BR2_INSTALL_LIBSTDCPP \
+comment "botan needs a toolchain w/ C++, gcc >= 10"
+	depends on !BR2_INSTALL_LIBSTDCPP \
 		|| !BR2_TOOLCHAIN_GCC_AT_LEAST_10
 	depends on BR2_PACKAGE_BOTAN_ARCH_SUPPORTS

package/botan/botan.mk

@@ -48,6 +48,12 @@ else
 BOTAN_CONF_OPTS += --without-stack-protector
 endif
 
+ifeq ($(BR2_TOOLCHAIN_HAS_THREADS_NPTL),y)
+BOTAN_CONF_OPTS += --with-os-feature=threads
+else
+BOTAN_CONF_OPTS += --without-os-feature=threads
+endif
+
 ifeq ($(BR2_TOOLCHAIN_USES_UCLIBC),y)
 BOTAN_CONF_OPTS += --without-os-feature=explicit_bzero,getauxval,getentropy
 endif