config: Extend GNU CI config groups

The current CI on tf.org only has a GNU compiler supported. Add the GNU
only configs for per patch/nightly job.

This patch should revert once the CI on tf.org support Clang compiler.

Signed-off-by: Karl Zhang <karl.zhang@arm.com>
Change-Id: I03e17608991df6e5c9c1afb7d50402abf2b73039
1 file changed