vboot_reference: add creation of GBB blob to gbb_utility

Non-x86 platforms (ex, ARM) may need to create GBB from scratch.
The new "create" (-c) creates a GBB blob by given property maximum sizes.
The list must follow same order as specified in GBB header.

BUG=chromium-os:1302
TEST=gbb_utility -c 0x100,0x1000,0x03DE80,0x1000 gbb.blob
     gbb_utility -s --hwid='test' gbb_blob
     gbb_utility -s --rootkey='some_rootkey' gbb_blob
     gbb_utility -g --hwid --rootkey='rk.bin' gbb_blob # output hwid=test

Change-Id: Ic854609effa32020f9536bc2d3f8457dff1c3719

Review URL: http://codereview.chromium.org/6173001
2 files changed