ice: fix setting l4 port flag when adding filter

Accidentally filter flag for none encapsulated l4 port field is always
set. Even if user wants to add encapsulated l4 port field.

Remove this unnecessary flag setting.

Fixes: 9e300987 ("ice: VXLAN and Geneve TC support")
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Tested-by: Sandeep Penigalapati <sandeep.penigalapati@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>