net: move HDS config from ethtool state

Separate the HDS config from the ethtool state struct.
The HDS config contains just simple parameters, not state.
Having it as a separate struct will make it easier to clone / copy
and also long term potentially make it per-queue.

Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://patch.msgid.link/20250119020518.1962249-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/netdev_queues.h

@@ -4,6 +4,16 @@
 
 #include <linux/netdevice.h>
 
+/**
+ * struct netdev_config - queue-related configuration for a netdev
+ * @hds_thresh:		HDS Threshold value.
+ * @hds_config:		HDS value from userspace.
+ */
+struct netdev_config {
+	u32	hds_thresh;
+	u8	hds_config;
+};
+
 /* See the netdev.yaml spec for definition of each statistic */
 struct netdev_queue_stats_rx {
 	u64 bytes;