patches: openwrt: add libevent2 host build

patches/openwrt/to-upstream/0017-libevent2-add-host-build.patch

+From 4383917d6ab17810286e8cfae7c035363abb03d4 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Karel=20Ko=C4=8D=C3=AD?= <cynerd@email.cz>
+Date: Sun, 10 Mar 2019 10:50:53 +0100
+Subject: [PATCH] libevent2: add host build
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Signed-off-by: Karel Kočí <cynerd@email.cz>
+---
+ package/libs/libevent2/Makefile | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/package/libs/libevent2/Makefile b/package/libs/libevent2/Makefile
+index f7223a01d6..b77fff1517 100644
+--- a/package/libs/libevent2/Makefile
++++ b/package/libs/libevent2/Makefile
+@@ -24,6 +24,7 @@ PKG_FIXUP:=autoreconf
+ PKG_INSTALL:=1
+ PKG_BUILD_PARALLEL:=1
+ 
++include $(INCLUDE_DIR)/host-build.mk
+ include $(INCLUDE_DIR)/package.mk
+ 
+ define Package/libevent2/Default
+@@ -153,6 +154,7 @@ define Package/libevent2-pthreads/install
+ 	$(CP) $(PKG_INSTALL_DIR)/usr/lib/libevent_pthreads-2.1.so.* $(1)/usr/lib/
+ endef
+ 
++$(eval $(call HostBuild))
+ $(eval $(call BuildPackage,libevent2))
+ $(eval $(call BuildPackage,libevent2-core))
+ $(eval $(call BuildPackage,libevent2-extra))
+-- 
+2.21.0
+