igc: Correct Wake-on-LAN filter programming

The attach path translated WUC.APME into a saved link-change filter,
then advertised magic-packet wake. Suspend removed unselected magic,
unicast, and mu

igc: Correct Wake-on-LAN filter programming

The attach path translated WUC.APME into a saved link-change filter,
then advertised magic-packet wake. Suspend removed unselected magic,
unicast, and multicast bits from that saved value, commonly leaving no
hardware wake filter at all. The destructive masking also made later
capability changes ineffective.

Advertise the I225/I226 wake filters whenever PCI power management is
available and enable magic-packet wake by default. Build a fresh WUFC
mask for every suspend, and explicitly clear WUC, WUFC, and PCI PME when
wake is disabled.

Require the PCI power-management capability to report D3hot PME support
before advertising or arming wake. A PM capability alone does not mean
the function can signal PME from the state used during system sleep.

Reconstruct RAR0, the multicast table, and the receive filter after the
stop-time reset so unicast and multicast wake use the current interface
state. Keep the PHY powered while wake is armed, drain pending PCIe
transactions, and disable bus mastering before D3.

Clear the sticky base and extended wake status before arming filters.
On resume, report the saved hardware wake cause, clear the device wake
source, and then clear PCI PME. Run the DMA-fencing sequence even when
wake programming fails, while allowing shutdown to continue after
logging the failure. Explicitly restore PCI bus mastering during
initialization so an iflib-local resume after another child rejects
suspend can restart the device.

Restore the Intel shared code PHY power down test from DPDK. The
FreeBSD split inverted the reset-block condition, so its dormant hook
would power down only when firmware explicitly vetoed the operation.

Do not copy the generic legacy management test verbatim. The I225 and
I226 define MANC bits 0 and 1 as flow-control and NC-SI discard
controls, not SMBus and ASF enable bits. Preserve the link when the
documented TCO receive path is enabled; the shared reset-block test
separately honors the firmware keep-link-up veto. This follows section
8.21.1 of the Foxville Software User Manual.

Evaluate management pass-through at each suspend. When neither a host
wake filter nor management requires the link, invoke the shared-code
power-down hook before D3. Leave a management-owned link untouched and
restore a link previously powered down by the driver without another
PHY reset. This follows DPDK's stop/start pairing without changing
ordinary ifconfig down behavior.

The implementation was checked against the Intel I225/I226 programming
model, the Intel Linux igc lifecycle, and DPDK.

On an I225-LM, a device-only D3 test observed PME for a valid magic
packet and no PME with every host wake filter disabled. Both cases
resumed to D0 with the link and configured addresses operational.

The I225 system also completed a full ACPI S3 cycle and resumed with
link, configured addresses, and traffic operational.

On an I226-V, a device-only D3 test changed PMCSR accordingly after a
magic packet. With dev.igc.0.wake enabled, a full ACPI S3 cycle
remained asleep until a delayed magic packet and resumed with link,
addresses, and traffic operational.

PR: 282140
Obtained from: DPDK (shared-code power-down structure)
MFC after: 2 weeks

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