libyaml: fix libyaml-legal-info build failure

libyaml: fix libyaml-legal-info build failure

LICENSE file changed and hash hasn't been recalculated, this leads to
libyaml-legal-info build failure.

Kirill Simonov Copyright now covers 2006-2016.
Ingy döt Net Copyright has been added instead for 2017-2018.

Recalculate sha256 locally and substitute it in libyaml.hash file.

Fixes:
http://autobuild.buildroot.net/results/c10/c10baf6e9bae92d515264b677eeb1ce6c98c793d//
http://autobuild.buildroot.net/results/c66/c66ddb56fecf1570a8669bd9d8824cd2132f9776//
http://autobuild.buildroot.net/results/84e/84e9530aff0c981a009416f31470133fb2114421//

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>