package/libva-intel-driver: bump version to 1.6.0

Upstream hash is in sha1 format, like before. It is wrongly announced
as md5 in the release mail, so I added a note to the hash file.

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>