ci: Add extra Kconfigs required by Docker on x86
The x86_64 defconfig does not enable CONFIG_BPF_SYSCALL, unlike arm64's which does. Docker gives this error without it:
---8<--- docker: Error response from daemon: failed to create task for container: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: error during container init: error setting cgroup config for procHooks process: bpf_prog_query(BPF_CGROUP_DEVICE) failed: function not implemented: unknown ---8<---
Signed-off-by: Ryan Roberts ryan.roberts@arm.com