net: fec: fix typos found by codespell

codespell has found some typos in the comments, fix them.

Reviewed-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Csókás, Bence <csokas.bence@prolan.hu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://patch.msgid.link/20250618-fec-cleanups-v4-1-c16f9a1af124@pengutronix.de


Signed-off-by: Jakub Kicinski <kuba@kernel.org>