net: dsa: microchip: use DSA_TAG_PROTO without _VALUE define

Correct the use of define DSA_TAG_PROTO_LAN937X_VALUE to
DSA_TAG_PROTO_LAN937X to improve readability.
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Link: https://lore.kernel.org/r/20231206160124.1935451-1-sean@geanix.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/microchip/ksz_common.c

@@ -2712,7 +2712,7 @@ static enum dsa_tag_protocol ksz_get_tag_protocol(struct dsa_switch *ds,
 		proto = DSA_TAG_PROTO_KSZ9477;
 
 	if (is_lan937x(dev))
-		proto = DSA_TAG_PROTO_LAN937X_VALUE;
+		proto = DSA_TAG_PROTO_LAN937X;
 
 	return proto;
 }