MAINTAINERS: replace Clark Wang with Frank Li for Freescale FEC

MAINTAINERS: replace Clark Wang with Frank Li for Freescale FEC

We have not seen tags from Clark for FEC in over 5 years.
He has some limited recent activity on the mailing list in other
NXP subsystems (stmmac, phy). Wei Fang and Shenwei Wang are active,
with decent review coverage (61%).

Frank Li has been reviewing code actively more recenty, let's
make it official.

Subsystem FREESCALE IMX / MXC FEC DRIVER
  Changes 57 / 92 (61%)
  Last activity: 2026-02-10
  Wei Fang <wei.fang@nxp.com>:
    Author 25eb3058eb70 2026-02-10 00:00:00 33
    Tags 25eb3058eb70 2026-02-10 00:00:00 61
  Shenwei Wang <shenwei.wang@nxp.com>:
    Author d466c16026e9 2025-09-14 00:00:00 6
    Tags d466c16026e9 2025-09-14 00:00:00 6
  Clark Wang <xiaoning.wang@nxp.com>:
  Top reviewers:
    [23]: Frank.Li@nxp.com
    [17]: andrew@lunn.ch
    [4]: csokas.bence@prolan.hu
    [3]: horms@kernel.org
    [2]: maxime.chevallier@bootlin.com
  INACTIVE MAINTAINER Clark Wang <xiaoning.wang@nxp.com>

Reviewed-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260303215339.2333548-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>