octeontx2-af: configure default CPT credits for CN10KA B0

The maximum CPT credits that RXC can use are now configurable on CN10KA B0
through a hardware CSR. This patch sets the default value to optimize peak
performance, aligning it with other chip versions.

Signed-off-by: Srujana Challa <schalla@marvell.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>