mt76x0: fix memory leak during hw probe

Fix memory leak during hw probe if mt76x0_register_device fails
since MT76_STATE_INITIALIZED has not set yet and mt76x0_cleanup
does not free tx/rx queues and mcu buffers

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>