In addition to being able to flash a ROM from the GUI, it would also be
useful for a user to be able to add a GPG key to their keyring using the
flashing tool. This change adds the ability for a user to edit both a
ROM located on a USB key and also edit the running BIOS by using
flashrom to make a local copy of the running BIOS, edit it, then reflash
it. This also supports the upcoming delete feature in CBFS for
circumstances where keyring files already exist within CBFS.
To keep the flash logic simpler the GUI logic has been split into a
flash-gui.sh program so flash.sh behaves closer to the original flashrom
scripts it was based from. I've also removed the previous flashrom
scripts and incorporated their options into flash.sh. Finally I set
CONFIG_BOARD via the Makefile instead of setting a duplicate option in
each board's config.
