Without the latest headers present our toolchain and various other
components may be incorrectly configured for older features when
running a newer kernel. Let's get this guy back up to date as part
of the toolchain update process.
Note that rsync is required as a build dependency as it was removed
from the solbuild images a long time ago, but is required within the
Signed-off-by: Ikey Doherty <email@example.com>