mkosi: Update bundled kconfig

mkosi: Update bundled kconfig

- Remove useless serial console configs
- Add CONFIG_SERIAL_8250_PCI so that qemu's virtconsole works properly
- Add CONFIG_DMI and CONFIG_DMI_SYSFS so that SMBIOS credentials work
- Add CONFIG_IKCONFIG and CONFIG_IKCONFIG_PROC so we can read the
  current kernel config from /proc/config.gz
- Add CONFIG_IOSCHED_BFQ to get rid of a udev error on boot on Fedora
- Add CONFIG_HW_RANDOM_VIRTIO to get hw rng in qemu
- Add CONFIG_SECURITY_YAMA to get rid of warning from sysctl on boot
- Add CONFIG_VSOCKETS and CONFIG_VIRTIO_VSOCKETS to enable vsock support