Security update for ovmf (moderate)

This update for ovmf fixes the following issues:

Security issues fixed:

• CVE-2018-3613: Fixed AuthVariable Timestamp zeroing issue on
  APPEND_WRITE (bsc#1115916).
• CVE-2017-5731: Fixed privilege escalation via processing of malformed
  files in TianoCompress.c (bsc#1115917).
• CVE-2017-5732: Fixed privilege escalation via processing of malformed
  files in BaseUefiDecompressLib.c (bsc#1115917).
• CVE-2017-5733: Fixed privilege escalation via heap-based buffer overflow
  in MakeTable() function (bsc#1115917).
• CVE-2017-5734: Fixed privilege escalation via stack-based buffer
  overflow in MakeTable() function (bsc#1115917).
• CVE-2017-5735: Fixed privilege escalation via heap-based buffer overflow
  in Decode() function (bsc#1115917).

Non security issues fixed:

• Fixed an issue with the default owner of PK/KEK/db/dbx and make the
  auto-enrollment only happen at the very first time. (bsc#1117998)

This update was imported from the SUSE:SLE-15:Update update project.