iwlwifi: pcie: fix the byte count table format for 22560 devices

Starting from 22560, the byte count is expected to be in
bytes and we have now 14 bits. Ajust the code to this.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>