sfc: Add explicit RX queue flag to channel

The PTP channel will have its own RX queue even though it's not
a regular traffic channel.

Original work by Ben Hutchings <bhutchings@solarflare.com>

Signed-off-by: Stuart Hodgson <smhodgson@solarflare.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 7ab1232..24a78a3 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -242,6 +242,8 @@
 /**
  * struct efx_rx_queue - An Efx RX queue
  * @efx: The associated Efx NIC
+ * @core_index:  Index of network core RX queue.  Will be >= 0 iff this
+ *	is associated with a real RX queue.
  * @buffer: The software buffer ring
  * @rxd: The hardware descriptor ring
  * @ptr_mask: The size of the ring minus 1.
@@ -263,6 +265,7 @@
  */
 struct efx_rx_queue {
 	struct efx_nic *efx;
+	int core_index;
 	struct efx_rx_buffer *buffer;
 	struct efx_special_buffer rxd;
 	unsigned int ptr_mask;
@@ -1047,7 +1050,7 @@
 
 static inline bool efx_channel_has_rx_queue(struct efx_channel *channel)
 {
-	return channel->channel < channel->efx->n_rx_channels;
+	return channel->rx_queue.core_index >= 0;
 }
 
 static inline struct efx_rx_queue *