Bug#659404: laptop-detect: Use /sys/devices/virtual/dmi/id/chassis_type as alternative to dmidecode?

[Simó Albert i Beltran]

Hello,

Thanks for your contribution to laptop-detect.
I'm doing an ITA of this package and I would like include your 
contribution.

I created the following commit but please do a merge request if you 
prefer.
https://gitlab.com/debiants/laptop-detect/commit/ac832efccff4ca87a5ca01a7c3cfbb808fa386ba


Thanks again.