i40e/i40evf: add driver version string to driver version command

The driver version string was added to this struct to be passed
down through the firmware to low-level NC-SI functions. We tell
the firmware about the length of the ASCII string not counting
any terminating null.

Change-ID: I09ac98ff9b869e8661c55fc6a5c98808fc280c91
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Anjali Singhai <anjali.singhai@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>