nati_x86_64_defconfig: Enable config options required for docker

[gratian]

Enable the necessary configuration options required in order to run docker containers on NI Linux RT.

Testing

• Built new kernel and installed on cRIO-9042
• Validated docker is functional by:
  • installing docker from feeds with: opkg install docker-ce
  • removing the conflicting LabVIEW cpuset script: rm /etc/rc5.d/S01nicreatecpusets (note: de-conflicting this is being worked on separately)
  • tested docker with docker run --rm hello-world and docker run -it ubuntu bash
• Checked size increase: bzImage ~ 334.5 Kbytes, modules ~ 252 Kbytes
• Performance tests left to ATSes

[bstreiff]

also cherry-picked into 6.1