VLR_Name and MME_Name contain DNS-encoded hostnames, not charstrings

TS 29.118 Section 9.4.13 is very clear abou the MME name, i.e. that it
is encoded as a DNS name, with each label prefixed by the binary length
of the given label.

However, the MME_Name and VLR_Name types in SGsAP_Types.ttcn so far were
defined as "charstring", which is incompatible with the above.

Change-Id: Ic38234ee1469b557d46397f54fad80241b692baa
Signed-off-by: Harald Welte <laforge@gnumonks.org>
diff --git a/src/SGsAP_Types.ttcn b/src/SGsAP_Types.ttcn
index a7b9d19..a38a93f 100644
--- a/src/SGsAP_Types.ttcn
+++ b/src/SGsAP_Types.ttcn
@@ -289,7 +289,7 @@
 {
   BIT8                   iEI,
   LIN1                   lengthIndicator,
-  charstring             name
+  octetstring            name
 } with {
   variant "PRESENCE (iEI = '00001001'B)";
   variant (lengthIndicator) "LENGTHTO (name)"
@@ -678,7 +678,7 @@
 {
   BIT8                       iEI,
   LIN1                       lengthIndicator,
-  charstring                 name
+  octetstring                name
 } with {
   variant "PRESENCE (iEI = '00000010'B)";
   variant (lengthIndicator) "LENGTHTO (name)"