Add Arm MPS3 AN524 Target and Trusted Firmware-M

[microbuilder]

This PR enables the Arm MPS3 development board using the AN524 (Arm Cortex-M33) application image:

• It has been tested using QEMU (6.0.0) and on actual HW. Instructions on building QEMU from source to enable functional AN524 support are included.
• Trusted Firmware-M (TF-M) has been enabled as an external project in cmake, which will be downloaded, built and linked as part of the standard build process. TF-M integration is currently based on the 1.3.0 release.

Note: This PR requires changes to threadx, proposed here: https://github.com/azure-rtos/threadx/pull/126 ... once those changes are merged in, the threadx sobmodule reference in this PR can be updated from url = https://github.com/Linaro/threadx.git to the original url = https://github.com/azure-rtos/threadx.git.

Co-authored-by: Jimmy Brisson [email protected] Co-authored-by: Devaraj Ranganna [email protected] Signed-off-by: Kevin Townsend [email protected]

[ghost]

All CLA requirements met.

[ryanwinter]

Thanks @microbuilder, we can review this for inclusion when the new threadx version is released.