octeontx2-af: Increase maximum BPID channels

Any NIX interface type can have maximum 256 channels. So increased the
backpressure ID count to 256 so that it can cover cn9k and cn10k SoCs that
have different NIX interface types with varied maximum channels.

Signed-off-by: Radha Mohan Chintakuntla <radhac@marvell.com>
Link: https://lore.kernel.org/r/20240326184514.1628284-1-radhac@marvell.com


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