Update mbedtls to 3.6.0

Change-Id: I03e5b4387b8915bdd40e468b844b3c31d76e25fc
Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>
(cherry picked from commit 6b73bd360f28191c758ec22485d03157c6857b31)
diff --git a/script/tf-coverity/common-def.sh b/script/tf-coverity/common-def.sh
index 42cd1ae..a781389 100644
--- a/script/tf-coverity/common-def.sh
+++ b/script/tf-coverity/common-def.sh
@@ -79,7 +79,7 @@
 
 # mbed TLS source tag to checkout when building Trusted Firmware with
 # cryptography support (e.g. for Trusted Board Boot feature).
-MBED_TLS_SOURCES_TAG="mbedtls-2.28.8"
+MBED_TLS_SOURCES_TAG="mbedtls-3.6.0"
 
 ARMCLANG_PATH="$(set_armclang_toolchain)"