Adding fix to convert latitude/longitude degrees to floating point format from fixed point format

Change-Id: Ibcfeae69e4f60423c87a0fdb8666192a1ca5dc0c
Reviewed-on: https://code.wireshark.org/review/5726
Petri-Dish: Alexis La Goutte <alexis.lagoutte@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Anders Broman <a.broman58@gmail.com>