Add support for dissecting the old-style Broadcom tag with Ethertype 0x8874,
this was supported by switches like Broadcom BCM5325. Newer switches use a
different tag format (with no Ethertype) which will be supported later.
Change-Id: Iec26f8d13058399a35fb258ccadc48f7f5ac8474
Reviewed-on: https://code.wireshark.org/review/23592
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>
Reviewed-by: Michael Mann <mmann78@netscape.net>