ran_msg_a.c: use gsm0808_create_cipher2()

Use new API in Cipher Mode Command to prepare for A5/4 support.

Depends: Ib3906085e0c6e5a496a9f755f0f786238a86ca34 (libosmocore)
Related: SYS#5324
Change-Id: Ib238d367b8d5d07b6ab4cb2e48fbf4ce22ca4476
diff --git a/TODO-RELEASE b/TODO-RELEASE
index d0852fc..2297063 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -7,3 +7,4 @@
 # If any interfaces have been added since the last public release: c:r:a + 1.
 # If any interfaces have been removed or changed since the last public release: c:r:0.
 #library	what		description / commit summary line
+libosmocore	>1.5.1		A5/4 support requires new API gsm0808_create_cipher2()