Convert TZ target name to test spec platform name
Convert TZ target name to test spec platform name

1.  All TZ targets should have name pattern: PLATFORM_[PSA_]S/NS, where:
    (1) 'PLATFORM' for test spec platform name
    (2) 'PSA' is optional to distinguish PSA/non-PSA targets, especially when
        both PSA/non-PSA targets are supported
    (3) 'S'/'NS' for secure/non-secure targets
2. Secure target may participate in Greentea, so its name is also truncated here.

mbedmicro/mbed,andcor02/mbed-os,kjbracey-arm/mbed,andcor02/mbed-os,andcor02/mbed-os,kjbracey-arm/mbed,kjbracey-arm/mbed,andcor02/mbed-os,kjbracey-arm/mbed,mbedmicro/mbed,andcor02/mbed-os,mbedmicro/mbed,andcor02/mbed-os,mbedmicro/mbed,mbedmicro/mbed