Enable GRUB support on the compatible platforms

[rsalveti, Oct 11, 2012] Please also add some more extra info about what needs to be done, so we can properly cover it during this cycle still. Thanks.
[rsalveti, Oct 24, 2012] Missing information for the blueprint, needs to be postponed and discussed at Connect.
[leif-lindholm, Oct 24, 2012] Filesystem/partition layout and similar things, as well as the packaging's interface to the firmware, to be discussed in http://summit.linaro.org/lce12/meeting/20960/grub2-standardisation/
[leif-lindholm, Nov 07, 2012] Basic build/installation instructions added to https://wiki.linaro.org/OfficeofCTO/Grub2.
[asac, 2012-11-19] this needs proper headline and acceptance.
[asac, 2012-11-19] also, its not clear where we will have grub included in future.
[fboudra, 2012-11-21] Note: at the moment, it doesn't work out of the box, users should boot then run grub-install. It's a known issue and we need to investigate how to provide a better user experience.

Meta:
Headline: Versatile Express hardware pack includes now Linaro GRUB, enabled for U-Boot platform on ARM architecture.
Acceptance: VE hwpack contains grub-arm package. VE can boot with Linaro GRUB using U-Boot port.
Roadmap id: CARD-173

Output:
Linaro grub package: https://launchpad.net/~linaro-maintainers/+archive/overlay/+packages?field.name_filter=grub&field.status_filter=published&field.series_filter=
VE hwpack configurations:
http://bazaar.launchpad.net/~linaro-maintainers/linaro-images/hwpack.precise.linaro-vexpress/revision/16
http://bazaar.launchpad.net/~linaro-maintainers/linaro-images/hwpack.precise.linaro-lt-vexpress/revision/18

Work items:
Package grub for compatible platforms: DONE
Update compatible patforms hwpacks: DONE