Merge remote-tracking branch 'remotes/kraxel/tags/misc-20190111-pull-request' into...

misc: fix seabios cross build.

# gpg: Signature made Fri 11 Jan 2019 11:46:47 GMT
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/misc-20190111-pull-request:
  roms: seabios: Rename CROSS_COMPILE to CROSS_PREFIX

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