i40evf: use correct types

Don't use uint32_t type the kernel. Use u32 instead. No functional
change.

Change-ID: I77bbf3b6464edaef747c7104b43534032a4dba63
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>