r8169: small 8101 comment

Extracted from version 1.001.00 of Realtek's r8101.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Cc: Edward Hsu <edward_hsu@realtek.com.tw>
diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index a6fea19..49e599bc 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -1165,6 +1165,10 @@
 	 * if needed:
 	 *
 	 * (RTL_R32(TxConfig) & 0x700000) == 0x500000 ? 8168Bf : 8168Be
+	 *
+	 * Same thing for the 8101Eb and the 8101Ec:
+	 *
+	 * (RTL_R32(TxConfig) & 0x700000) == 0x200000 ? 8101Eb : 8101Ec
 	 */
 	const struct {
 		u32 mask;