Move the declaration of kSRTPProfiles to ssl/internal.h

(This will cause the compile to warn us if we fail to keep the types in
sync.)

Change-Id: I8c395ca595d895d108c5ba8f4c46ecca620c405e
diff --git a/ssl/internal.h b/ssl/internal.h
index 1a28245..297c155 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h
@@ -790,6 +790,7 @@
 extern const SSL3_ENC_METHOD TLSv1_1_enc_data;
 extern const SSL3_ENC_METHOD TLSv1_2_enc_data;
 extern const SSL3_ENC_METHOD SSLv3_enc_data;
+extern const SRTP_PROTECTION_PROFILE kSRTPProfiles[];
 
 void ssl_clear_cipher_ctx(SSL *s);
 int ssl_clear_bad_session(SSL *s);