Add Rx descriptor limit for number of segments per MTU.
PMD doesn't support Jumbo Rx scatter gather hence set 1 segment per
MTU. Some applications can adjust mbuf_size based on this value.
For others PMD detects the condition where Rx packet length cannot
be held by configured mbuf size and logs the message.
Signed-off-by: Rasesh Mody <rmody@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>