ixgbe: use u32 instead of __u32 in model header

I incorrectly used __u32 types where we should be using u32 types when
I added the ixgbe_model.h file.

Fixes: 9d35cf06 ("net: ixgbe: add minimal parser details for ixgbe")
Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>