[third_party/bcmdhd] Extract crossdriver symbols.

Some symbols (typically constants and macros) are present in both BCMDHD
and Fuchsia brcmfmac drivers. This change extracts symbols that are
needed in Fuchsia brcmfmac for future CLs that will implement WifiStats.

Bug: 29698
Change-Id: I30fda6f0b042a69d90d2004a631a1a0de4b78de6
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/bcmdhd/+/401994
Reviewed-by: Joshua Conner <joshconner@google.com>
4 files changed