tnccs-11: Remove legacy TNCCS-1.1 implementation

There is no reason to keep this around anymore (has been superseded by
TNCCS-2.0 a long time ago).  Removed the corresponding test scenarios.

Since this is the last user of libxml, also removed those references.

testing/scripts/recipes/013_strongswan.mk

@@ -42,7 +42,6 @@ CONFIG_OPTS = \
 	--enable-tnc-pdp \
 	--enable-tnc-imc \
 	--enable-tnc-imv \
-	--enable-tnccs-11 \
 	--enable-tnccs-20 \
 	--enable-tnccs-dynamic \
 	--enable-imc-test \