MAINTAINERS: remove Jonathan Lemon from OpenCompute PTP

MAINTAINERS: remove Jonathan Lemon from OpenCompute PTP

We have not seen emails or tags from Jonathan in over 5 years,
and there is no recent mailing list activity.
Vadim Fedorenko is active.

Subsystem OPENCOMPUTE PTP CLOCK DRIVER
  Changes 49 / 130 (37%)
  Last activity: 2025-11-25
  Jonathan Lemon <jonathan.lemon@gmail.com>:
  Vadim Fedorenko <vadim.fedorenko@linux.dev>:
    Author d3ca2ef0c915 2025-09-19 00:00:00 5
    Tags 648282e2d1e5 2025-11-25 00:00:00 20
  Top reviewers:
    [7]: horms@kernel.org
    [4]: jiri@nvidia.com
    [3]: richardcochran@gmail.com
    [2]: aleksandr.loktionov@intel.com
  INACTIVE MAINTAINER Jonathan Lemon <jonathan.lemon@gmail.com>

Add Jonathan to CREDITS as the initial author of ptp_ocp.

Acked-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260303215339.2333548-9-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>