Add a script to explicitly handle multiple Surface kernel versions being
installed in parallel, sorting kernels by timestamp and choosing the
latest one.
Further, add support for rEFInd by updating the vmlinuz file timestamp
to ensure it's always seen as the last modified file (which will be
picked by rEFInd as the "default" kernel in that directory).
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>