net: fec: remove .ndo_poll_controller to avoid deadlocks

mainline inclusion
from mainline-v6.10-rc1
commit c2e0c58b25a0a0c37ec643255558c5af4450c9f5
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6S6S
CVE: CVE-2024-38597

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c2e0c58b25a0a0c37ec643255558c5af4450c9f5



--------------------------------

There is a deadlock issue found in sungem driver, please refer to the
commit ac0a230f719b ("eth: sungem: remove .ndo_poll_controller to avoid
deadlocks"). The root cause of the issue is that netpoll is in atomic
context and disable_irq() is called by .ndo_poll_controller interface
of sungem driver, however, disable_irq() might sleep. After analyzing
the implementation of fec_poll_controller(), the fec driver should have
the same issue. Due to the fec driver uses NAPI for TX completions, the
.ndo_poll_controller is unnecessary to be implemented in the fec driver,
so fec_poll_controller() can be safely removed.

Fixes: 7f5c6add ("net/fec: add poll controller function for fec nic")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://lore.kernel.org/r/20240511062009.652918-1-wei.fang@nxp.com


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

Conflicts:
	drivers/net/ethernet/freescale/fec_main.c
[Adjust context conflicts]
Signed-off-by: Liu Chuang <liuchuang40@huawei.com>