Fix compilation errors

Fix compilation errors when `MBEDTLS_DTLS_SRTP` not set
1. Add file missed in previous commmit.
2. In sample applications, set `DFL_FORCE_SRTP_PROFILE` to 0.

Signed-off-by: Johan Pascal <johan.pascal@belledonne-communications.com>
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 83f2f42..6983347 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -881,6 +881,13 @@
 }
 mbedtls_ssl_srtp_profile;
 
+typedef struct
+{
+    const mbedtls_ssl_srtp_profile   profile;
+    const char                      *name;
+}
+mbedtls_ssl_srtp_profile_info;
+
 typedef struct mbedtls_dtls_srtp_info_t
 {
     mbedtls_ssl_srtp_profile chosen_dtls_srtp_profile; /*!< negotiated SRTP profile */
@@ -3233,6 +3240,15 @@
  * \return         0 on succes, MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL if the key buffer is too small to hold the generated key
  */
 int mbedtls_ssl_get_dtls_srtp_key_material( const mbedtls_ssl_context *ssl, unsigned char *key, size_t *key_len );
+
+/**
+ * \brief                  Utility function to get information on dtls srtp profile.
+ *
+ * \param profile          The dtls-srtp profile id to get info on.
+ *
+ * \return         mbedtls_ssl_srtp_profile_info* on success, NULL if not found
+ */
+const mbedtls_ssl_srtp_profile_info *mbedtls_ssl_dtls_srtp_profile_info_from_id( mbedtls_ssl_srtp_profile profile );
 #endif /* MBEDTLS_SSL_DTLS_SRTP */
 
 /**
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index d9d5cad..4ae740c 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -151,7 +151,7 @@
 #define DFL_SKIP_CLOSE_NOTIFY   0
 #define DFL_QUERY_CONFIG_MODE   0
 #define DFL_USE_SRTP            0
-#define DFL_SRTP_FORCE_PROFILE  MBEDTLS_SRTP_UNSET_PROFILE
+#define DFL_SRTP_FORCE_PROFILE  0
 #define DFL_SRTP_MKI            ""
 
 #define GET_REQUEST "GET %s HTTP/1.0\r\nExtra-header: "
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 2db5887..137838c 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -184,7 +184,7 @@
 #define DFL_NSS_KEYLOG_FILE     NULL
 #define DFL_QUERY_CONFIG_MODE   0
 #define DFL_USE_SRTP            0
-#define DFL_SRTP_FORCE_PROFILE  MBEDTLS_SRTP_UNSET_PROFILE
+#define DFL_SRTP_FORCE_PROFILE  0
 #define DFL_SRTP_SUPPORT_MKI    0
 
 #define LONG_RESPONSE "<p>01-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n" \