gitlab-ci: Enable debug uart config options for UP Squared 6000 board
This commit adds the EXTRACONFIG parameter to the target platform configurations in the gitlab CI. The config options in this parameter will be enabled on top of the selected defconfig.
In particular, this enables the required config options to have debug UART enabled on x64 UP Squared 6000 boards.
Signed-off-by: Ariel D'Alessandro ariel.dalessandro@collabora.com