r8169: disable detection of chip versions 49 and 50

It seems these chip versions never made it to the wild. Therefore
disable detection and if nobody complains remove support completely
later.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/realtek/r8169_main.c

@@ -1978,8 +1978,11 @@ static enum mac_version rtl8169_get_mac_version(u16 xid, bool gmii)
 
 		/* 8168EP family. */
 		{ 0x7cf, 0x502,	RTL_GIGA_MAC_VER_51 },
-		{ 0x7cf, 0x501,	RTL_GIGA_MAC_VER_50 },
-		{ 0x7cf, 0x500,	RTL_GIGA_MAC_VER_49 },
+		/* It seems this chip version never made it to
+		 * the wild. Let's disable detection.
+		 * { 0x7cf, 0x501,      RTL_GIGA_MAC_VER_50 },
+		 * { 0x7cf, 0x500,      RTL_GIGA_MAC_VER_49 },
+		 */
 
 		/* 8168H family. */
 		{ 0x7cf, 0x541,	RTL_GIGA_MAC_VER_46 },