net: broadcom: bcm4908_enet: report queued and transmitted bytes

This allows BQL to operate avoiding buffer bloat and reducing latency.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20221031104856.32388-1-zajec5@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>