tfm: Harded build against TF-M built with unsecure keys

Introduce Kconfig option in zephyr build system that reflects the TF-M
cmake config variable with the same default value for dummy provisioning
and have it satisfy the IAK present requirement.
This configuration is not suitable for production, and by having this
in zephyr configuration we can have this as part of the hardened
configuration check.

Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>