update seabios to 1.7.5.1 stable release

git shortlog since 1.7.5:

Hannes Reinecke (1):
      megasas: read addional PCI I/O bar

Kevin O'Connor (5):
      boot: Change ":rom%d" boot order rom instance to ":rom%x"
      vgabios: Return from handle_1011() if handler found.
      Don't enable thread preemption during S3 resume vga option rom execution.
      build: Avoid absolute paths during "whole-program" compiling.
      ehci: Fix bug in hub port assignment

Marcel Apfelbaum (1):
      hw/pci: reserve IO and mem for pci express downstream ports with no devices attached

Markus Armbruster (1):
      boot: Fix boot order for SCSI target, lun > 9

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Merge remote-tracking branch 'remotes/kraxel/tags/pull-seabios-1.7.5.1-20141113-1' into staging

update seabios to 1.7.5.1 stable release

# gpg: Signature made Thu 13 Nov 2014 11:03:05 GMT using RSA key ID D3E87138
# 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>"

* remotes/kraxel/tags/pull-seabios-1.7.5.1-20141113-1:
  update seabios to 1.7.5.1 stable release

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