net: enetc: reimplement RFS/RSS memory clearing as PCI quirk

net: enetc: reimplement RFS/RSS memory clearing as PCI quirk

The workaround implemented in commit 3222b5b613db ("net: enetc:
initialize RFS/RSS memories for unused ports too") is no longer
effective after commit 6fffbc7ae137 ("PCI: Honor firmware's device
disabled status"). Thus, it has introduced a regression and we see AER
errors being reported again:

$ ip link set sw2p0 up && dhclient -i sw2p0 && ip addr show sw2p0
fsl_enetc 0000:00:00.2 eno2: configuring for fixed/internal link mode
fsl_enetc 0000:00:00.2 eno2: Link is Up - 2.5Gbps/Full - flow control rx/tx
mscc_felix 0000:00:00.5 swp2: configuring for fixed/sgmii link mode
mscc_felix 0000:00:00.5 swp2: Link is Up - 1Gbps/Full - flow control off
sja1105 spi2.2 sw2p0: configuring for phy/rgmii-id link mode
sja1105 spi2.2 sw2p0: Link is Up - 1Gbps/Full - flow control off
pcieport 0000:00:1f.0: AER: Multiple Corrected error received: 0000:00:00.0
pcieport 0000:00:1f.0: AER: can't find device of ID0000

Rob's suggestion is to reimplement the enetc driver workaround as a
PCI fixup, and to modify the PCI core to run the fixups for all PCI
functions. This change handles the first part.

We refactor the common code in enetc_psi_create() and enetc_psi_destroy(),
and use the PCI fixup only for those functions for which enetc_pf_probe()
won't get called. This avoids some work being done twice for the PFs
which are enabled.

Fixes: 6fffbc7ae137 ("PCI: Honor firmware's device disabled status")
Link: https://lore.kernel.org/netdev/CAL_JsqLsVYiPLx2kcHkDQ4t=hQVCR7NHziDwi9cCFUFhx48Qow@mail.gmail.com/
Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>