xz: bump version to 5.2.0
-Bump version to 5.2.0
-Update hash file
-Use xz tarball instead of bz2 to save space and bandwidth
Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>