Remove unused |ccm128_context| in crypto/modes/internal.h.

Note that this structure has a weak pointer to the key, which was a
problem corrected in the AES-GCM code in
0f8bfdeb3383749eecfefb17a36416e6b35fa10c. Also, it uses |void *|
instead of |const AES_KEY *| to refer to that key.

Change-Id: I70e632e3370ab27eb800bc1c0c64d2bd36b7cafb
Reviewed-on: https://boringssl-review.googlesource.com/7123
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/crypto/modes/internal.h b/crypto/modes/internal.h
index 51b6431..12e6df5 100644
--- a/crypto/modes/internal.h
+++ b/crypto/modes/internal.h
@@ -179,16 +179,6 @@
   block128_f block;
 };
 
-struct ccm128_context {
-  union {
-    uint64_t u[2];
-    uint8_t c[16];
-  } nonce, cmac;
-  uint64_t blocks;
-  block128_f block;
-  void *key;
-};
-
 #if defined(OPENSSL_X86) || defined(OPENSSL_X86_64)
 /* crypto_gcm_clmul_enabled returns one if the CLMUL implementation of GCM is
  * used. */