net: enetc: fix sleeping function called from rcu_read_lock() context

net: enetc: fix sleeping function called from rcu_read_lock() context

The rcu_read_lock() has been introduced in __ethtool_get_ts_info() since
the commit 4c61d809cf60 ("net: ethtool: Fix suspicious rcu_dereference
usage"). Therefore, the device drivers cannot use any sleeping functions
when implementing the callback of ethtool_ops::get_ts_info(). Currently,
pci_get_slot() is used in enetc_get_ts_info(), but it calls down_read()
which might sleep, so this is a potential issue. Therefore, to fix this
issue, pci_get_domain_bus_and_slot() is used to replace pci_get_slot()
in enetc_get_ts_info().

Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Closes: https://lore.kernel.org/netdev/20250918124823.t3xlzn7w2glzkhnx@skbuf/
Fixes: f5b9a1cde0a2 ("net: enetc: add PTP synchronization support for ENETC v4")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20250919084509.1846513-2-wei.fang@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>