fuel-plugin: update libudev version

fuel-plugin: update libudev version

Canonical have bumped libudev_204 from package 5ubuntu20.15 to 20.18

Change-Id: Iba01e7c50a43522e895b6abad095d919811b2ecc
Reviewed-by: Jonas Bjurel <jonas.bjurel@ericsson.com>
Reviewed-by: Mark D. Gray <mark.d.gray@intel.com>
Reviewed-by: Ruijing Gao <ruijing.guo@intel.com>
Reviewed-by: Donald Dugger <donald.d.dugger@intel.com>
Reviewed-by: Michal Skalski <mskalski@mirantis.com>
Reviewed-by: Narinder Gupta <narinder.gupta@canonical.com>
(cherry picked from commit de6318b49dc91a95154c30d6721a863d8ab7a1b7)