Hi all,

I want to simplify the flag TFM_PLATFORM in build system. TF-M now already supports two different ways to choose specific platform, for example AN521:

- Absolute path: '<tf-m path>/platform/ext/target/arm/mps2/an521'

- Relative path: 'arm/mps2/an21'

Recently I have uploaded a [tf-m patch]https://review.trustedfirmware.org/c/TF-M/trusted-firmware-m/+/14260 to support platform name:

- Platform name: 'an521'

I think it will be more convenient for developers to use:

- Users don't need to remember and type the absolute or relative path, only target platform name is enough.

- If the structure of certain platform is changed, the default build command of TFM_PLATFORM is same.

I'd be very grateful if you can give any suggestion or enhancement for me. Thanks.

Best Regards Jianliang Shen