Rename ssl_internal.h to ssl_misc.h

Signed-off-by: Chris Jones <christopher.jones@arm.com>
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 27e0246..be68bcd 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -30,7 +30,7 @@
 #endif
 
 #include "mbedtls/ssl.h"
-#include "ssl_internal.h"
+#include "ssl_misc.h"
 #include "mbedtls/debug.h"
 #include "mbedtls/error.h"