wifi: mt76: Fix memory leak destroying device

wifi: mt76: Fix memory leak destroying device

All MT76 rx queues have an associated page_pool even if the queue is not
associated to a NAPI (e.g. WED RRO queues with WED enabled). Destroy the
page_pool running mt76_dma_cleanup routine during module unload.
Moreover returns pages to the page pool if WED is not enabled for WED RRO
queues.

Fixes: 950d0abb5cd94 ("wifi: mt76: mt7996: add wed rx support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20251208-mt76-fix-memory-leak-v1-1-cba813fc62b8@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>