ci/nouveau: Add nouveau support to the rootfs.

This required updating the kernel to 5.16.12 to get a more stable boot
process.  That kernel rebuild caused an update of the container with
piglit which that was missed in a previous MR, so we got new xfails in x86
swrast.  Also, including modules on arm64 exposed a bug in v3d's
poe-powered.sh rsyncing of modules.

Acked-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15201>

.gitlab-ci/container/build-kernel.sh

@@ -28,7 +28,7 @@ if [[ -n ${DEVICE_TREES} ]]; then
     cp ${DEVICE_TREES} /lava-files/.
 fi
 
-if [[ ${DEBIAN_ARCH} = "amd64" ]]; then
+if [[ ${DEBIAN_ARCH} = "amd64" || ${DEBIAN_ARCH} = "arm64" ]]; then
     make modules
     INSTALL_MOD_PATH=/lava-files/rootfs-${DEBIAN_ARCH}/ make modules_install
 fi