net: usb: lan78xx: Rename EVENT_LINK_RESET to EVENT_PHY_INT_ACK

net: usb: lan78xx: Rename EVENT_LINK_RESET to EVENT_PHY_INT_ACK

The EVENT_LINK_RESET macro currently triggers deferred work after a PHY
interrupt. Prior to PHYLINK conversion, this work included reconfiguring
the MAC and PHY, effectively performing a 'link reset'.

However, after porting the driver to the PHYLINK framework, the logic
associated with this event now solely handles the acknowledgment of
the PHY interrupt. The MAC and PHY reconfiguration is now managed by
PHYLINK's dedicated callbacks.

To accurately reflect its current, narrowed functionality, rename
EVENT_LINK_RESET to EVENT_PHY_INT_ACK.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/20250618122602.3156678-3-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>