microcode_ctl security, bug fix and enhancement update

[2:2.1-73.11.0.1]

• for Intel, do not trigger load if on-disk microcode is not an update [Orabug: 30634727]
• set early_microcode=‘no’ in virtualized guests to avoid early load bugs [Orabug: 30618736]
• ensure late loading fixes are present on 4.1.12-* and 4.14.35-*
• enable early and late load for 5.4.17-*
• enable early loading for 06-4f-01 caveat
• remove no longer appropriate caveats for 06-2d-07 and 06-55-04
  [2:2.1-73.11]
• Update Intel CPU microcode to microcode-20210608 release:
  • Fixes in releasenote.md file.
    [2:2.1-73.10]
• Make intel-06-2d-07, intel-06-4e-03, intel-06-4f-01, intel-06-55-04,
  intel-06-5e-03, intel-06-8c-01, intel-06-8e-9e-0x-0xca,
  and intel-06-8e-9e-0x-dell caveats dependent on intel caveat.
• Enable 06-8c-01 microcode update by default.
• Enable 06-5e-03 microcode update by default (#1897684).