GitLab

Added note regarding use of SPDX identifiers following this example:
https://github.com/pocoproject/poco/blob/develop/LICENSE



Change-Id: I22a280bce57f9145e4786c5ad32f663c2c9c6545
Signed-off-by: Jilayne Lovejoy <jilayne.lovejoy@arm.com>
Signed-off-by: Dan Handley <dan.handley@arm.com>

Change-Id: Ic7fb61aabae1d515b9e6baf3dd003807ff42da60

- Add instructions for contributing to ARM Trusted Firmware.

- Update copyright text in all files to acknowledge contributors.

Change-Id: I9311aac81b00c6c167d2f8c889aea403b84450e5