Merge remote-tracking branch 'remotes/kraxel/tags/sirius/ipxe-20200908-pull-request...

ipxe: update to aug 2020 snapshot.

# gpg: Signature made Tue 08 Sep 2020 07:09:26 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/sirius/ipxe-20200908-pull-request:
  ipxe: update binaries
  ipxe: drop ia32 efi roms
  ipxe: update submodule

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>