B2Qt NXP iMX8Mini and iMX8QM devices to RTA for Qt 6

Who
As a B2Qt developer I want to verify my implementation before delivering it to community and customers with appropriate devices.

What
NXP iMX8 boards are key targets for Qt 6. Qt 6 shall support 1) NXP iMX8Mini and 2) NXP iMX8QM both with ARM-v8A-64bit and Yocto 3.1 (gcc 9.3) https://intranet.qt.io/display/QTRD/Discussion+of+Qt+6.0%2C+6.1%2C+6.2+Supported+Functionality 

Why
For Qt6 there is new Yocto version (Dunfell) introduced for these two boards.

Definition of Done (DoD)
NXP devices iMX8Mini and iMX8QM are added to RTA. RTA executes automatic tests for B2Qt. RTA provides results for both devices. Automatic tests are meaningful and do not provide false positives nor false negatives.

More info
https://wiki.yoctoproject.org/wiki/Releases 
https://www.nxp.com/products/processors-and-microcontrollers/arm-processors/i-mx-applications-processors/i-mx-8-processors/i-mx-8m-mini-arm-cortex-a53-cortex-m4-audio-voice-video:i.MX8MMINI 
https://www.nxp.com/products/processors-and-microcontrollers/arm-processors/i-mx-applications-processors/i-mx-8-processors/i-mx-8m-family-armcortex-a53-cortex-m4-audio-voice-video:i.MX8M  (Q = Quad, meaning number of cores)