i40e: driver core headers

This patch contains the main driver header files, containing
structures and data types specific to the linux driver.

i40e_osdep.h contains some code that helps us adapt our OS agnostic code to
Linux.

Signed-off-by: Jesse Brandeburg <[email protected]>
Signed-off-by: Shannon Nelson <[email protected]>
CC: PJ Waskiewicz <[email protected]>
CC: [email protected]
Tested-by: Kavindya Deegala <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>

Author: jbrandeb