net: macb: fix unregister_netdev call order in macb_remove()

net: macb: fix unregister_netdev call order in macb_remove()

When removing a macb device, the driver calls phy_exit() before
unregister_netdev(). This leads to a WARN from kernfs:

  ------------[ cut here ]------------
  kernfs: can not remove 'attached_dev', no directory
  WARNING: CPU: 1 PID: 27146 at fs/kernfs/dir.c:1683
  Call trace:
    kernfs_remove_by_name_ns+0xd8/0xf0
    sysfs_remove_link+0x24/0x58
    phy_detach+0x5c/0x168
    phy_disconnect+0x4c/0x70
    phylink_disconnect_phy+0x6c/0xc0 [phylink]
    macb_close+0x6c/0x170 [macb]
    ...
    macb_remove+0x60/0x168 [macb]
    platform_remove+0x5c/0x80
    ...

The warning happens because the PHY is being exited while the netdev
is still registered. The correct order is to unregister the netdev
before shutting down the PHY and cleaning up the MDIO bus.

Fix this by moving unregister_netdev() ahead of phy_exit() in
macb_remove().

Fixes: 8b73fa3ae02b ("net: macb: Added ZynqMP-specific initialization")
Signed-off-by: luoguangfei <15388634752@163.com>
Link: https://patch.msgid.link/20250818232527.1316-1-15388634752@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>