gsm0808: Introduce gsm0808_old_bss_to_new_bss_info_att_tlvdef

Introduce TLV attribute definition for "Old BSS to New BSS Information"
container.

Related: SYS#5337
Change-Id: I0e55e947b6fef6dad0cf1a6c16b781bef4cc76c5
diff --git a/TODO-RELEASE b/TODO-RELEASE
index 53401ec..ed04a14 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -8,4 +8,4 @@
 # If any interfaces have been removed or changed since the last public release: c:r:0.
 #library	what			description / commit summary line
 libosmovty	_LAST_OSMOVTY_NODE 	Raise _LAST_OSMOVTY_NODE by introducing some RESERVED*_NODE
-libosmogsm      gsm0808_old_bss_to_new_bss_info ABI break (struct changes size)
+libosmogsm      gsm0808_old_bss_to_new_bss_info ABI break (struct changes size), gsm0808_old_bss_to_new_bss_info_att_tlvdef symbol added