net: stmmac: Don't modify the global ptp ops directly

net: stmmac: Don't modify the global ptp ops directly

The stmmac_ptp_clock_ops are copied into the stmmac_priv structure
before being registered to the PTP core. Some adjustments are made prior
to that, such as the number of snapshots or max adjustment parameters.

Instead of modifying the global definition, then copying into the local
private data, let's first copy then modify the local parameters.

Reviewed-by: Daniel Machon <daniel.machon@microchip.com>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20241112170658.2388529-2-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>