b43: Implement dynamic PHY API

This patch implements a dynamic "ops" based PHY API. This is needed in order to conveniently support future PHY types to avoid the "switch"-hell.

This patch does not change any functionality. It just moves lots of code from one place to another and adjusts it for the changed data structures.

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Due to the size, this patch is not inlined.
Please find it here:
http://bu3sch.de/patches/wireless-testing/20080827-1750/patches/003-b43-phy-ops.patch

You may notice that after this patch is applied the file "phy.c" will still contain some unused code.
This will be fixed in a future patch by moving that code to "phy_a.c". I do not want to further bloat this patch. It's already big enough.

I'm sorry for pushing such a big patch upstream. :)

Please apply for the next bugfix push, if you want to get Dave _really_ mad. Apply to 2.6.28, if you decide that he would probably kill you. ;) (I think he would *hint*)