RANAP: Split FormatInformationParameter / SDUParameterItem

The definition of the above data types as per 3GPP specs results in a
SEQUENCE_OF() an anonymous structure, which is slightly inconvenient to
use.  So let's split the SEQUENCE OF part and the actual definition of
the item in separate types.
diff --git a/asn1/ranap/RANAP-IEs.asn b/asn1/ranap/RANAP-IEs.asn
index 8d09bee..9593ee8 100644
--- a/asn1/ranap/RANAP-IEs.asn
+++ b/asn1/ranap/RANAP-IEs.asn
@@ -1745,7 +1745,8 @@
 }
 -- SDU-ErrorRatio = mantissa * 10^-exponent
 
-SDU-FormatInformationParameters ::= SEQUENCE (SIZE (1..maxRAB-SubflowCombination)) OF
+SDU-FormatInformationParameters ::= SEQUENCE (SIZE (1..maxRAB-SubflowCombination)) OF SDU-FormatInformationParameterItem
+SDU-FormatInformationParameterItem ::=
 	SEQUENCE {
 		subflowSDU-Size			SubflowSDU-Size 	OPTIONAL,
 		rAB-SubflowCombinationBitRate	RAB-SubflowCombinationBitRate 	OPTIONAL,
@@ -1753,7 +1754,8 @@
 		...
 	}
 
-SDU-Parameters ::= SEQUENCE (SIZE (1..maxRAB-Subflows)) OF
+SDU-Parameters ::= SEQUENCE (SIZE (1..maxRAB-Subflows)) OF SDU-ParameterItem
+SDU-ParameterItem ::=
 	SEQUENCE {
 		sDU-ErrorRatio			SDU-ErrorRatio OPTIONAL
 		-- This IE shall be present if the Delivery Of Erroneous SDU IE is set to "Yes" or "No" --,