net: bcmgenet: add RX_CLS_LOC_ANY support

If a matching flow spec exists its current location is as good
as ANY. If not add the new flow spec at the first available
location.

Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20221019215123.316997-1-opendmb@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>