Add support for IEEE 802.15.4 32-bit FCS

Make FCS length a variable.
Modify protocol configuration to include FCS type option.

Change-Id: I1e08f5b6b43907833464c20d798163343ce67a76
Reviewed-on: https://code.wireshark.org/review/32139


Petri-Dish: Stig Bjørlykke <stig@bjorlykke.org>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>