Check for libxml when building tnccs_11, use autoconf libxml CFLAGS/LIBS

configure.in

@@ -234,7 +234,7 @@ if test x$fips_prf = xtrue; then
 	fi
 fi
 
-if test x$smp = xtrue; then
+if test x$smp = xtrue -o x$tnccs_11 = xtrue; then
 	xml=true
 fi
 

src/libcharon/plugins/tnccs_11/Makefile.am

@@ -1,10 +1,11 @@
 
 INCLUDES = -I$(top_srcdir)/src/libstrongswan -I$(top_srcdir)/src/libhydra \
-	-I$(top_srcdir)/src/libcharon -I$(top_srcdir)/src/libtls \
-	`xml2-config --cflags`
+	-I$(top_srcdir)/src/libcharon -I$(top_srcdir)/src/libtls ${xml_CFLAGS}
 
 AM_CFLAGS = -rdynamic
 
+libstrongswan_tnccs_11_la_LIBADD = ${xml_LIBS}
+
 if MONOLITHIC
 noinst_LTLIBRARIES = libstrongswan-tnccs-11.la
 else