config: increase max queues per port

config: increase max queues per port

The default value of RTE_MAX_QUEUES_PER_PORT is 256, which is too small
for some configurations for i40e. There will return an error when
configured queue number is larger than 256 in rte_eth_dev_configure().

For example, in vHost sample, PF queue number: 64,
configured vmdq pool number: 63, each vmdq pool has 4 queues,
there will be required 316 queues in a port.

Signed-off-by: Jijiang Liu <jijiang.liu@intel.com>
Acked-by: Helin Zhang <helin.zhang@intel.com>