ethtool: Add comments for valid use of flow types

#define WAKE_MAGICSECURE	(1 << 6) /* only meaningful if WAKE_MAGIC */

/* L3-L4 network traffic flow types */

#define	TCP_V4_FLOW	0x01

#define	UDP_V4_FLOW	0x02

#define	SCTP_V4_FLOW	0x03

#define	AH_ESP_V4_FLOW	0x04

#define	TCP_V6_FLOW	0x05

#define	UDP_V6_FLOW	0x06

#define	SCTP_V6_FLOW	0x07

#define	AH_ESP_V6_FLOW	0x08

#define	AH_V4_FLOW	0x09

#define	ESP_V4_FLOW	0x0a

#define	AH_V6_FLOW	0x0b

#define	ESP_V6_FLOW	0x0c

#define	IP_USER_FLOW	0x0d

#define	IPV4_FLOW	0x10

#define	IPV6_FLOW	0x11

#define	TCP_V4_FLOW	0x01	/* hash or spec (tcp_ip4_spec) */

#define	UDP_V4_FLOW	0x02	/* hash or spec (udp_ip4_spec) */

#define	SCTP_V4_FLOW	0x03	/* hash or spec (sctp_ip4_spec) */

#define	AH_ESP_V4_FLOW	0x04	/* hash only */

#define	TCP_V6_FLOW	0x05	/* hash only */

#define	UDP_V6_FLOW	0x06	/* hash only */

#define	SCTP_V6_FLOW	0x07	/* hash only */

#define	AH_ESP_V6_FLOW	0x08	/* hash only */

#define	AH_V4_FLOW	0x09	/* hash or spec (ah_ip4_spec) */

#define	ESP_V4_FLOW	0x0a	/* hash or spec (esp_ip4_spec) */

#define	AH_V6_FLOW	0x0b	/* hash only */

#define	ESP_V6_FLOW	0x0c	/* hash only */

#define	IP_USER_FLOW	0x0d	/* spec only (usr_ip4_spec) */

#define	IPV4_FLOW	0x10	/* hash only */

#define	IPV6_FLOW	0x11	/* hash only */

/* L3-L4 network traffic flow hash options */

#define	RXH_L2DA	(1 << 1)