BCM43438A0 is an old version of CYW4348A1; it is not a broad-market chip.
I would suggest you to get in touch with our marketing team or your local Cypress contact team in order to get support for your request.
Yes, I think the chip is long dead now! Unfortunately I built up a couple of samples using them and it would be quite nice to try out the correctness of the board before I do the next revision...I have no intention of the files having any life beyond that testing. In response to your suggestion I've just pinged my local FAE but I'd still appreciate the files if anyone happens to have them.
We cannot provide you the files here on community. Our FAE will guide you properly to get the files from internal source.