We're struggling with the 6.5 kernel as the serial port getty doesn't appears sometimes
leading to failures in CI. Add a workaround of sending some newlines as a way of
unblocking the kernel/release issues whilst we try and work out how to get to the bottom
of the issue.
(From OE-Core rev: 0a65f0d272895ba13c8c133ee71f3605d765a8a7)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>