buildroot

cmake: bump version to 3.8.2

cmake depends on rhash, but host-cmake doesn't. This is because we use
the bundled dependencies for host-cmake but not for target.

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>