fam15 vendorcode: Change license to BSD from AMD software license

fam15 vendorcode (src/vendorcode/amd/agesa/f15tn) was licensed under the
AMD software license agreement. Change this license to 3-clause BSD.

Change-Id: I7cab09bb58ef7cd24602628e2278672d577214a2
Signed-off-by: Siyuan Wang <SiYuan.Wang@amd.com>
Signed-off-by: Siyuan Wang <wangsiyuanbuaa@gmail.com>
Reviewed-on: http://review.coreboot.org/3414
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
745 files changed