Add empty directory 'overlays/arm64-{target,development}'

Signed-off-by: Héctor Orón Martínez <hector.oron@collabora.co.uk>
Reviewed-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Andrew Shadura <andrew.shadura@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D7289