TF-M: Adds venv support for TF-M containers

Adds building support for using venv for python3 on TF-M jammy and
bionic containers.

Change-Id: I879e1782cad71b6f4b5f6ed25a94098b693b7ef7
Signed-off-by: Matthew Dalzell <matthew.dalzell@arm.com>
2 files changed