canutils: Update LICENSE field version GPLv2
canutils: Update LICENSE field version GPLv2

* Updated LICENSE field version from generic LGPL to GPLv2 to
  reflect the actual license and license version of the code.
* This change was back-ported from oe-core

Signed-off-by: Chase Maupin <5a5662f468a76e0fc4391e65fb9f536df44d7380@ti.com>

sledz/oe,sledz/oe,mrchapp/arago-oe-dev,sledz/oe,mrchapp/arago-oe-dev,mrchapp/arago-oe-dev,mrchapp/arago-oe-dev,sledz/oe,mrchapp/arago-oe-dev,sledz/oe,sledz/oe,mrchapp/arago-oe-dev,mrchapp/arago-oe-dev,sledz/oe