Bump version

./scripts/bump_version.sh --version 2.28.6 --so-crypto 7 --so-x509 1 --so-tls 14

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/doxygen/mbedtls.doxyfile b/doxygen/mbedtls.doxyfile
index f6f160d..1939ac9 100644
--- a/doxygen/mbedtls.doxyfile
+++ b/doxygen/mbedtls.doxyfile
@@ -1,4 +1,4 @@
-PROJECT_NAME           = "Mbed TLS v2.28.5"
+PROJECT_NAME           = "Mbed TLS v2.28.6"
 OUTPUT_DIRECTORY       = ../apidoc/
 FULL_PATH_NAMES        = NO
 OPTIMIZE_OUTPUT_FOR_C  = YES