Add tag for dra7xx-evm with CAN setup and have releng use it

Changes submitted, waiting approval/merge from @Jan-Simon Moeller

ci-management changes:
https://gerrit.automotivelinux.org/gerrit/19393
https://gerrit.automotivelinux.org/gerrit/19781

test definition changes:
https://gerrit.automotivelinux.org/gerrit/19741
https://gerrit.automotivelinux.org/gerrit/19739

Using lavacli to query tags: https://gerrit.automotivelinux.org/gerrit/#/c/19393/

Tag "CAN" added

Step 1: @Corentin Labbe: can you add a `CAN` tag to the dra7 connected to our AGL LAVA slave?

Step 2: modify ci-management scripts to query and save any device tags when checking for available devices.  Somewhere around here[1].

Step 3: Modify releng-scripts to have an additional --test-append argument, so additional test plans can be added to the defaults defined in templates/config/default.cfg

Step 4: When LAVA jobs are created by releng-scripts, convert any device tags to "--test-append <testplan>" arguments to create-jobs.py.  Somewhere in this script[2]

[1] https://git.automotivelinux.org/ci-management/tree/jjb/common/include-agl-lava-labs-prepare.sh#n72

[2] https://git.automotivelinux.org/ci-management/tree/jjb/common/include-agl-run-test-short.sh