Unbreakable Enterprise kernel security update

[4.14.35-2047.511.5.4]

• x86/speculation: Add knob for eibrs_retpoline_enabled (Patrick Colp) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Extend our code to properly support eibrs+lfence and eibrs+retpoline (Patrick Colp) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Update link to AMD speculation whitepaper (Kim Phillips) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Use generic retpoline by default on AMD (Kim Phillips) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting (Josh Poimboeuf) [Orabug: 33922122] {CVE-2021-26341}
• Documentation/hw-vuln: Update spectre doc (Peter Zijlstra) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Add eIBRS + Retpoline options (Peter Zijlstra) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE (Peter Zijlstra (Intel)) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Merge one test in spectre_v2_user_select_mitigation() (Borislav Petkov) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Update ALTERNATIVEs to (more closely) match upstream (Patrick Colp) [Orabug: 33922122] {CVE-2021-26341}
• x86/speculation: Fix bug in retpoline mode on AMD with (Patrick Colp) [Orabug: 33922122] {CVE-2021-26341}
• bpf: Add kconfig knob for disabling unpriv bpf by default (Daniel Borkmann) [Orabug: 33926438]