[flashrom] [patch] partial write test script

[David Hendricks]

After a few tries at manually verifying partial writes and realizing that
it's awfully tedious to do any exhaustive testing, I hastily threw together
a shell script to help automate the process. Since there are others on this
list doing similar things, I figured it might be helpful to throw it up
here.

Note: It's unfinished and probably has bugs, but I figure it's at least a
start, even if only to kickstart a conversation about how to test partial
writes in a standard and useful manner.

Signed-off-by: David Hendricks