Merge remote-tracking branch 'remotes/stsquad/tags/pull-travis-updates-140618-1'...

Merge remote-tracking branch 'remotes/stsquad/tags/pull-travis-updates-140618-1' into staging

Travis updates

  - show config.log when failing
  - reduce time for gprof build
  - reduce time for alternate trace builds

# gpg: Signature made Thu 14 Jun 2018 20:29:59 BST
# gpg:                using RSA key FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>"
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* remotes/stsquad/tags/pull-travis-updates-140618-1:
  travis: reduce time taken for trace-backend testing
  travis: reduce coverage of gprof build
  travis: display config.log when configure fails

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