gen_test_desc: support specifying RF-A configuration

Extend the test description to allow specifying RF-A configuration.
All RF-A test configurations are grouped under the rfa-* category.
The expected format for specifying RF-A test configurations is as follows:
rfa_config, rmm_config, tf_config

Change-Id: I335805013057dc7c6c0f520020603a5d8ada67d8
Signed-off-by: Tomás González <tomasagustin.gonzalezorlando@arm.com>
2 files changed