Package firmware-intel-ucode: Information

- bump epoch (again) and restore old versioning.
- removed external microcode files:
  + sig 0x000306f2, pf_mask 0x6f, 2017-11-17, rev 0x003b (merged)
  + sig 0x000406f1, pf_mask 0xef, 2017-11-18, rev 0xb000025 (downgraded)
  + sig 0x00050654, pf_mask 0xb7, 2017-11-21, rev 0x200003a (obsoleted).

- Update to 20180108 (adapted debian changelog is below):
  * New upstream microcode data file 20180108
    + Updated Microcodes:
      sig 0x000306c3, pf_mask 0x32, 2017-11-20, rev 0x0023, size 23552
      sig 0x000306d4, pf_mask 0xc0, 2017-11-17, rev 0x0028, size 18432
      sig 0x000306e4, pf_mask 0xed, 2017-12-01, rev 0x042a, size 15360
      sig 0x000306f2, pf_mask 0x6f, 2017-11-17, rev 0x003b, size 33792
      sig 0x000306f4, pf_mask 0x80, 2017-11-17, rev 0x0010, size 17408
      sig 0x00040651, pf_mask 0x72, 2017-11-20, rev 0x0021, size 22528
      sig 0x00040661, pf_mask 0x32, 2017-11-20, rev 0x0018, size 25600
      sig 0x00040671, pf_mask 0x22, 2017-11-17, rev 0x001b, size 13312
      sig 0x000406e3, pf_mask 0xc0, 2017-11-16, rev 0x00c2, size 99328
      sig 0x00050654, pf_mask 0xb7, 2017-12-08, rev 0x200003c, size 27648
      sig 0x00050662, pf_mask 0x10, 2017-12-16, rev 0x0014, size 31744
      sig 0x00050663, pf_mask 0x10, 2017-12-16, rev 0x7000011, size 22528
      sig 0x000506e3, pf_mask 0x36, 2017-11-16, rev 0x00c2, size 99328
      sig 0x000706a1, pf_mask 0x01, 2017-12-26, rev 0x0022, size 73728
      sig 0x000806e9, pf_mask 0xc0, 2018-01-04, rev 0x0080, size 98304
      sig 0x000806ea, pf_mask 0xc0, 2018-01-04, rev 0x0080, size 98304
      sig 0x000906e9, pf_mask 0x2a, 2018-01-04, rev 0x0080, size 98304
      sig 0x000906ea, pf_mask 0x22, 2018-01-04, rev 0x0080, size 97280
      sig 0x000906eb, pf_mask 0x02, 2018-01-04, rev 0x0080, size 98304
    + Implements IBRS/IBPB support and enhances LFENCE: mitigation
      against Spectre (fixes CVE-2017-5715)
    + Very likely fixes several other errata on some of the processors
  * supplementary-ucode-CVE-2017-5715.d/: remove.
    + Downgraded microcodes:
      sig 0x000406f1, pf_mask 0xef, 2017-03-01, rev 0xb000021, size 26624
      sig 0x000506c9, pf_mask 0x03, 2017-03-25, rev 0x002c, size 16384
    + This removes IBRS/IBPB support for these two platforms when compared
      with the previous (and unofficial) release, 20171215.  We don't know
      why Intel declined to include these microcode updates (as well as
      several others) in the release.
  * source: remove superseded upstream data file: 20171117

- Added new CPU microcodes (microcode counterpart of the CVE-2017-5715
  kernel mitigation):
  + sig 0x000306f2, pf_mask 0x6f, 2017-11-17, rev 0x003b, size 33792
  + sig 0x000406f1, pf_mask 0xef, 2017-11-18, rev 0xb000025, size 27648
  + sig 0x00050654, pf_mask 0xb7, 2017-11-21, rev 0x200003a, size 27648