Deprecate comp128

Mark function as deprecated to discourage its usage: people should use
generic API in osmocom/crypt/auth.h
diff --git a/include/osmocom/gsm/comp128.h b/include/osmocom/gsm/comp128.h
index 33b997a..8ff76b1 100644
--- a/include/osmocom/gsm/comp128.h
+++ b/include/osmocom/gsm/comp128.h
@@ -8,11 +8,15 @@
 
 #include <stdint.h>
 
+#include <osmocom/core/defs.h>
+
 /*
- * Performs the COMP128 algorithm (used as A3/A8)
+ * Performs the COMP128v1 algorithm (used as A3/A8)
  * ki    : uint8_t [16]
  * srand : uint8_t [16]
  * sres  : uint8_t [4]
  * kc    : uint8_t [8]
  */
-void comp128(const uint8_t *ki, const uint8_t *srand, uint8_t *sres, uint8_t *kc);
+void comp128v1(const uint8_t *ki, const uint8_t *srand, uint8_t *sres, uint8_t *kc);
+
+void comp128(const uint8_t *ki, const uint8_t *srand, uint8_t *sres, uint8_t *kc) OSMO_DEPRECATED("Use generic API from osmocom/crypt/auth.h instead");