wifi: iwlwifi: disable multi rx queue for 9000

Multi rx queue allows to spread the load of the Rx streams on different
CPUs. 9000 series required complex synchronization mechanisms from the
driver side since the hardware / firmware is not able to provide
information about duplicate packets and timeouts inside the reordering
buffer.

Users have complained that for newer devices, all those synchronization
mechanisms have caused spurious packet drops. Those packet drops
disappeared if we simplify the code, but unfortunately, we can't have
RSS enabled on 9000 series without this complex code.

Remove support for RSS on 9000 so that we can make the code much simpler
for newer devices and fix the bugs for them.

The down side of this patch is a that all the Rx path will be routed to
a single CPU, but this has never been an issue, the modern CPUs are just
fast enough to cope with all the traffic.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20231017115047.2917eb8b7af9.Iddd7dcf335387ba46fcbbb6067ef4ff9cd3755a7@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>