Platform: MPS3: Move provisioning to common dir

Also include some minor changes in this commit:
- The dummy_provisioning_data.c file uses the keys from the
provisioning_config.cmake instead of having the keys
duplicated.
- Unused code removed from the python scripts

Change-Id: I949a0f19c9caaf5e93043881cdfa8052a3fad38f
Signed-off-by: Bence Balogh <bence.balogh@arm.com>
47 files changed