linux-firmware: Add firmware for RTL8168/8111E

Add firmware:
	rtl_nic/rtl8168e-1.fw
	rtl_nic/rtl8168e-2.fw
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

WHENCE

@@ -1559,6 +1559,8 @@ Driver: r8169 - RealTek 8169/8168/8101 ethernet driver.
 File: rtl_nic/rtl8168d-1.fw
 File: rtl_nic/rtl8168d-2.fw
 File: rtl_nic/rtl8105e-1.fw
+File: rtl_nic/rtl8168e-1.fw
+File: rtl_nic/rtl8168e-2.fw
 
 Licence:
  * Copyright © 2011, Realtek Semiconductor Corporation