eth_nxp_enet_qos should support IPV6 predefined multicast addresses

[theadib]

Describe the bug

I am using frdm_mcxn947 and IPV6 network stack.
on IPV6 when you ping to
ping ff02::1
all connected devices in the local network having IPV6 should respond.
The frdm_mcxn947 does not respond.
Retesting against frdm_k64f; that devkit/driver responds as expected.

The problem is the specific implementation of hardware MAC filtering in the SOC and how the driver handles it.
The SOC can handle individually select-able (list is not complete):

• 1(one) specific MAC address
• any multicast address,
• promiscuous mode (no hardware filtering)
  To note is the MAC hardware filter contains only 1(one) address entry and
  there is no possibility to further filter multicast (as the hash table implementation of the MK64)
  see also reference manual: 70.5.1.4 MAC Packet Filter (MAC_PACKET_FILTER)

The current driver does not set the "allow multicast" flag to allow multicast addresses to pass through. even when in IPV6 is enabled.

To Reproduce

west build -p -b frdm_mcxn947/mcxn947/cpu0 zephyr/samples/net/sockets/echo_server
west flash
ping ff02::1

Expected behavior

expected: on ping ff02::1
the device should respond with its IPV6 address

Impact

with the current implementation of the driver:

• addressing the device using unicast works but
• addressing the device using multicast method does not work as expected
• receiving application specific multicast packets does not work

IPV6 is only "halfway" implemented.
missing important and well known addressing methods

Logs and console output

Environment (please complete the following information):

I use:

• OS: Linux
• Toolchain: SDK 17.0
• Commit SHA or Version used: latest zephyr main 1207ccf
  as of 2024-dec-25

Additional context

https://en.wikipedia.org/wiki/Multicast_address
https://www.iana.org/assignments/ipv6-multicast-addresses/ipv6-multicast-addresses.xhtml

[theadib]

I filed a pull-request solving that issue #83416