chrony: add NTS option

Signed-off-by: Miroslav Lichvar <mlichvar0@gmail.com>

net/chrony/Makefile

@@ -22,18 +22,29 @@ PKG_CPE_ID:=cpe:/a:tuxfamily:chrony
 
 PKG_BUILD_DEPENDS:=pps-tools
 
+PKG_CONFIG_DEPENDS:= \
+	CONFIG_CHRONY_NTS
+
 include $(INCLUDE_DIR)/package.mk
 
 define Package/chrony
   SUBMENU:=Time Synchronization
   SECTION:=net
   CATEGORY:=Network
-  DEPENDS:=+libcap +libpthread
+  DEPENDS:=+libcap +libpthread +CHRONY_NTS:libgnutls +CHRONY_NTS:ca-bundle
   USERID:=chrony=323:chrony=323
   TITLE:=A versatile NTP client and server
   URL:=http://chrony.tuxfamily.org/
 endef
 
+define Package/chrony/config
+	if PACKAGE_chrony
+		config CHRONY_NTS
+			bool "Enable NTS support"
+			default n
+	endif
+endef
+
 define Package/chrony/description
 	An NTP client and server designed to perform well in a wide range
 	of conditions. It can synchronize the system clock with NTP servers,
@@ -52,7 +63,7 @@ CONFIGURE_ARGS+= \
 	--sysconfdir=/etc/chrony \
 	--prefix=/usr \
 	--chronyrundir=/var/run/chrony \
-	--disable-nts \
+	$(if $(CONFIG_CHRONY_NTS),,--disable-nts) \
 	--disable-readline \
 	--disable-rtc \
 	--disable-sechash \