ixgbe: remove unused enum latency_range

This enum is no longer needed after
commit: b4ded8327fe ("ixgbe: Update adaptive ITR algorithm")

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

@@ -2517,13 +2517,6 @@ static void ixgbe_configure_msix(struct ixgbe_adapter *adapter)
 	IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIAC, mask);
 }
 
-enum latency_range {
-	lowest_latency = 0,
-	low_latency = 1,
-	bulk_latency = 2,
-	latency_invalid = 255
-};
-
 /**
  * ixgbe_update_itr - update the dynamic ITR value based on statistics
  * @q_vector: structure containing interrupt and ring information