Restore bump version

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/doxygen/mbedtls.doxyfile b/doxygen/mbedtls.doxyfile
index 98b2d79..89048f2 100644
--- a/doxygen/mbedtls.doxyfile
+++ b/doxygen/mbedtls.doxyfile
@@ -1,4 +1,4 @@
-PROJECT_NAME           = "Mbed TLS v3.5.0"
+PROJECT_NAME           = "Mbed TLS v3.5.1"
 OUTPUT_DIRECTORY       = ../apidoc/
 FULL_PATH_NAMES        = NO
 OPTIMIZE_OUTPUT_FOR_C  = YES