Merge remote-tracking branch 'remotes/yongbok/tags/mips-20170222' into staging

Merge remote-tracking branch 'remotes/yongbok/tags/mips-20170222' into staging

MIPS patches 2017-02-22

Changes:
* Add MIPS Boston board support

# gpg: Signature made Wed 22 Feb 2017 00:08:00 GMT
# gpg:                using RSA key 0x2238EB86D5F797C2
# gpg: Good signature from "Yongbok Kim <yongbok.kim@imgtec.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 8600 4CF5 3415 A5D9 4CFA  2B5C 2238 EB86 D5F7 97C2

* remotes/yongbok/tags/mips-20170222:
  hw/mips: MIPS Boston board support
  hw: xilinx-pcie: Add support for Xilinx AXI PCIe Controller
  loader: Support Flattened Image Trees (FIT images)
  dtc: Update requirement to v1.4.2
  target-mips: Provide function to test if a CPU supports an ISA
  hw/mips_gic: Update pin state on mask changes
  hw/mips_gictimer: provide API for retrieving frequency
  hw/mips_cmgcr: allow GCR base to be moved

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