Forward-porting

[Matwey V. Kornilov]

Hi.

I hope this is right place to ask question on SubmittingPatches. I would
like to ask how correctly give the credits in the patch when I do
forward-porting.

There is some downstream kernel git where support of the some ARM board
is implemented for 3.12. What I did was to take dts, adopted it for
linux master and tested on upstream 3.18.1 (will also test with
3.19-rc), and found the board working.

I don't know if initial authors ever send this to upstream, but GPL
terms allows us to take this code right now.

In the initial commit tree, the code I tested is belong to several
different people, but I have to rebase the initial tree to take only
tiny needed part, so I can not just resend initial commits.

How should I properly fill "From:" field in the patch to specify initial
authors correctly?