i40e: don't use arrays for (src|dst)_ip

The code originally included src_ip and dst_ip with enough space to
support ipv6 filters. However, no actual support for ipv6 filters has
been implemented. Thus, remove the arrays and just use __be32 values.
Should ipv6 support be added in the future, we can replace these with
a union that has sizes for both values.

Change-Id: I1bc04032244a80eb6ebc8a4e6c723a4a665c1dd5
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>