[RFC 0/7] Update CI to using GCC 11.0 / LLVM-11

[Tom Rini]

Hey all,

This series does most of the work required to move to using GCC-11.0 to
build in CI.  The first thing is I realized I forgot to update buildman
to know to where to fetch gcc-11 from, but I'll take care of that later.
Next, this ends up using the last gcc-11 snapshot as the gcc-11.0
prebuilds aren't quite up on kernel.org, but will be soon.

The real issues here and I'd like some feedback on, and need some help
with are:
- grub + riscv32 + gcc-11 doesn't build, and this seems known but not
  addressed yet.  I don't know what we want to do here as it's for
  running some tests.
- I cannot get x86 to build.  With this series the failures are:
  https://source.denx.de/u-boot/u-boot/-/jobs/263745
  But I can't find a good way to address that multiple definition error
  of _X86EMU_env that doesn't break some other platform.  At heart,
  Chromebooks enable the emulation and we have both chromebook_link and
  chromebook_link64 as builds, so we have both X86_64 and !X86_64
  builds.  I don't know the best way to deal with this, but I also
  wonder if the bios_emulation code doesn't need a rather large cleaning
  perhaps?

-- 
Tom