nfp: ccm: increase message limits

Increase the batch limit to consume small message bursts more
effectively. Practically, the effect on the 'add' messages is not
significant since the mailbox is sized such that the 'add' messages are
still limited to the same order of magnitude that it was originally set
for.

Furthermore, increase the queue size limit to 1024 entries. This further
improves the handling of bursts of small control messages.

Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>