net: dsa: microchip: update tag_ksz masks for KSZ9477 family

Remove magic number 7 by introducing a GENMASK macro instead.
Remove magic number 0x80 by using the BIT macro instead.

Signed-off-by: Pieter Van Trappen <pieter.van.trappen@cern.ch>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20240909134301.75448-1-vtpieter@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/dsa/tag_ksz.c

@@ -178,8 +178,9 @@ MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8795, KSZ8795_NAME);
 
 #define KSZ9477_INGRESS_TAG_LEN		2
 #define KSZ9477_PTP_TAG_LEN		4
-#define KSZ9477_PTP_TAG_INDICATION	0x80
+#define KSZ9477_PTP_TAG_INDICATION	BIT(7)
 
+#define KSZ9477_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
 #define KSZ9477_TAIL_TAG_PRIO		GENMASK(8, 7)
 #define KSZ9477_TAIL_TAG_OVERRIDE	BIT(9)
 #define KSZ9477_TAIL_TAG_LOOKUP		BIT(10)
@@ -312,7 +313,7 @@ static struct sk_buff *ksz9477_rcv(struct sk_buff *skb, struct net_device *dev)
 {
 	/* Tag decoding */
 	u8 *tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
-	unsigned int port = tag[0] & 7;
+	unsigned int port = tag[0] & KSZ9477_TAIL_TAG_EG_PORT_M;
 	unsigned int len = KSZ_EGRESS_TAG_LEN;
 
 	/* Extra 4-bytes PTP timestamp */