Revert "feat(mbedtls): update to 3.4.0"

This reverts commit a66005cd87cc23c183f1af57047a7c18d4204905.

Reason for revert: Added too early

Change-Id: I08998c42640db3c7b3eb344a4c8cb8e57b7c8cd7
diff --git a/script/tf-coverity/common-def.sh b/script/tf-coverity/common-def.sh
index dae1e83..6e17ea9 100644
--- a/script/tf-coverity/common-def.sh
+++ b/script/tf-coverity/common-def.sh
@@ -80,7 +80,7 @@
 
 # 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-3.4.0"
+MBED_TLS_SOURCES_TAG="mbedtls-3.3.0"
 
 ARMCLANG_PATH="$(set_armclang_toolchain)"