selftests: drv-net: add tests for napi IRQ affinity notifiers

Add tests to check that the napi retained the IRQ after down/up,
multiple changes in the number of rx queues and after
attaching/releasing XDP program.

Tested on ice and idpf:

   # NETIF=<iface> tools/testing/selftests/drivers/net/hw/irq.py
    KTAP version 1
    1..4
    ok 1 irq.check_irqs_reported
    ok 2 irq.check_reconfig_queues
    ok 3 irq.check_reconfig_xdp
    ok 4 irq.check_down
    # Totals: pass:4 fail:0 xfail:0 xpass:0 skip:0 error:0

Tested-by: Ahmed Zaki <ahmed.zaki@intel.com>
Link: https://patch.msgid.link/20250224232228.990783-7-ahmed.zaki@intel.com


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