net/bnxt: fix Rx completion ring size calculation

net/bnxt: fix Rx completion ring size calculation

The size of the receive completion ring should be recalculated
when MTU is increased to a size that requires scattered receive
or when LRO is enabled. Move logic for this calculation from
the ring configuration path to the device start path.
   - Made size calculation dependent only on scattered_rx
     status.
   - Moved calculation of scattered_rx up in the initialization
     sequence.
   - Made LRO offload status part of scattered_rx calculation.

When the completion ring size is too small, completion overflows
can occur causing the ring to be disabled in hardware.

Fixes: 04067844a3e9 ("net/bnxt: reduce CQ queue size without aggregation ring")
Cc: stable@dpdk.org
Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>