net: lan966x: move unnecessary linux/sfp.h include

lan966x_phylink.c doesn't make use of anything from linux/sfp.h, so
remove this unnecessary include.
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://lore.kernel.org/r/E1oqzx9-001r9g-HV@rmk-PC.armlinux.org.ukSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/microchip/lan966x/lan966x_phylink.c

@@ -5,7 +5,6 @@
 #include <linux/device.h>
 #include <linux/netdevice.h>
 #include <linux/phy/phy.h>
-#include <linux/sfp.h>
 
 #include "lan966x_main.h"