r8169: use helper rtl_hw_aspm_clkreq_enable also in rtl_hw_start_8168g_2

One place in the driver was left where the open-coded functionality
hasn't been replaced with helper rtl_hw_aspm_clkreq_enable yet.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169_main.c

@@ -4710,8 +4710,7 @@ static void rtl_hw_start_8168g_2(struct rtl8169_private *tp)
 	rtl_hw_start_8168g(tp);
 
 	/* disable aspm and clock request before access ephy */
-	RTL_W8(tp, Config2, RTL_R8(tp, Config2) & ~ClkReqEn);
-	RTL_W8(tp, Config5, RTL_R8(tp, Config5) & ~ASPM_en);
+	rtl_hw_aspm_clkreq_enable(tp, false);
 	rtl_ephy_init(tp, e_info_8168g_2);
 }