net/iavf: enable IRQ mapping configuration for large VF

net/iavf: enable IRQ mapping configuration for large VF

The current IRQ mapping configuration only supports max 16 queues and
16 MSIX vectors. Change the queue vector mapping structure to indicate
up to 256 queues. A new opcode is used to handle the case with large
number of queues. To avoid adminq buffer size limitation, we support
to send the virtchnl message multiple times if needed.

Signed-off-by: Ting Xu <ting.xu@intel.com>
Acked-by: Beilei Xing <beilei.xing@intel.com>