ravb: Optimize ravb_emac_init_gbeth function

Optimize CXR31 register initialization on ravb_emac_init_gbeth
function.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Suggested-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/renesas/ravb_main.c

@@ -538,8 +538,7 @@ static void ravb_emac_init_gbeth(struct net_device *ndev)
 	/* E-MAC interrupt enable register */
 	ravb_write(ndev, ECSIPR_ICDIP, ECSIPR);
 
-	ravb_modify(ndev, CXR31, CXR31_SEL_LINK1, 0);
-	ravb_modify(ndev, CXR31, CXR31_SEL_LINK0, CXR31_SEL_LINK0);
+	ravb_modify(ndev, CXR31, CXR31_SEL_LINK0 | CXR31_SEL_LINK1, CXR31_SEL_LINK0);
 }
 
 static void ravb_emac_init_rcar(struct net_device *ndev)