PATCH v3 brcmfmac driver cleanup

[Ian Molton <ian@xxxxxxxxxxxxxx>]

Hi all,

Please find the 3rd revision of my cleanup patchset for brcmfmac.

I've done some further cleanup and it now handles SDIO the ay the MMC subsystem
was designed to.

I've also taken the liberty of greatly reducing the amount of indirection
used thoughout the SDIO code, which I think has improved readability quite a
lot.

Hope this finds you all well.

-Ian