[coreboot] licensing text

[mrnuke]

I meant to send this to the list, not Ron alone. Sorry Ron.

On Wednesday, February 12, 2014 10:18:33 AM you wrote:
> Note that if a file ALREADY has  notice in it, then we don't change
> anything. So, in the limit, we can start using this new notice for
> (e.g.) your stuff and only apply it as we wish.
> 
> That said, would you like to take a pass at the wording? Green, maybe :-)

Black and/or white!!

 * LICENSE_TAG: GPLv2+ (See README in top-level directory for explanation)
 * LICENSE_TAG: GPLv2 (See README in top-level directory for explanation)
 * LICENSE_TAG: BSD3c (See README in top-level directory for explanation)
 * LICENSE_TAG: BSD2c (See README in top-level directory for explanation)
 * Public domain (See README in top-level directory for explanation)

Alex