Bump version

./scripts/bump_version.sh --version 3.5.1 --so-crypto 15 --so-x509 6 --so-tls 20

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/doxygen/input/doc_mainpage.h b/doxygen/input/doc_mainpage.h
index f465a45..c391c59 100644
--- a/doxygen/input/doc_mainpage.h
+++ b/doxygen/input/doc_mainpage.h
@@ -10,7 +10,7 @@
  */
 
 /**
- * @mainpage Mbed TLS v3.5.0 API Documentation
+ * @mainpage Mbed TLS v3.5.1 API Documentation
  *
  * This documentation describes the internal structure of Mbed TLS.  It was
  * automatically generated from specially formatted comment blocks in