Fix Drilldown behavior with parent link when using keyboard.
Fix Drilldown behavior with parent link when using keyboard.

Fixes #10803

zurb/foundation-sites,dragthor/foundation-sites,denisahac/foundation-sites,abdullahsalem/foundation-sites,zurb/foundation,denisahac/foundation-sites,zurb/foundation,DaSchTour/foundation-sites,colin-marshall/foundation-sites,atmmarketing/foundation-sites,zurb/foundation-sites,colin-marshall/foundation-sites,DaSchTour/foundation-sites,dragthor/foundation-sites,atmmarketing/foundation-sites,dragthor/foundation-sites,abdullahsalem/foundation-sites,denisahac/foundation-sites,abdullahsalem/foundation-sites,zurb/foundation,atmmarketing/foundation-sites,zurb/foundation-sites,colin-marshall/foundation-sites