iwlwifi: pcie: add n_window/ampdu to tx_queue debugfs

Add the n_window and ampdu parameters so we can see them.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200417131727.a2cc1f36008f.Iea23802bb64a08de410223e9af4431dfcadf121b@changeid