r8169:add disable/enable RTL8168G pll function

RTL8168G also can disable/enable pll function.
Signed-off-by: NChun-Hao Lin <hau@realtek.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169.c

@@ -4375,6 +4375,7 @@ static void r8168_pll_power_down(struct rtl8169_private *tp)
 	case RTL_GIGA_MAC_VER_41:
 		rtl_w1w0_eri(tp, 0x1a8, ERIAR_MASK_1111, 0x00000000,
 			     0xfc000000, ERIAR_EXGMAC);
+		RTL_W8(PMCH, RTL_R8(PMCH) & ~0x80);
 		break;
 	}
 }
@@ -4399,6 +4400,7 @@ static void r8168_pll_power_up(struct rtl8169_private *tp)
 		break;
 	case RTL_GIGA_MAC_VER_40:
 	case RTL_GIGA_MAC_VER_41:
+		RTL_W8(PMCH, RTL_R8(PMCH) | 0xc0);
 		rtl_w1w0_eri(tp, 0x1a8, ERIAR_MASK_1111, 0xfc000000,
 			     0x00000000, ERIAR_EXGMAC);
 		break;