drm/ci: add tests on vkms

Add job that runs igt on top of vkms.

Acked-by: Maíra Canal <mcanal@igalia.com>
Acked-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Vignesh Raman <vignesh.raman@collabora.com>
Acked-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Tested-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Helen Koike <helen.koike@collabora.com>