rtlwifi: Add firmware v4.0 for RTL8188FU

rtl8xxxu supports this device now.

The firmware comes from the Realtek driver
RTL8188FU_Linux_v4.3.23.6_20964.20170110.

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>

WHENCE

@@ -3266,6 +3266,12 @@ File: rtlwifi/rtl8192eu_nic.bin
 File: rtlwifi/rtl8192eu_wowlan.bin
 File: rtlwifi/rtl8192eu_ap_wowlan.bin
 
+Info: rtl8188fu taken from Realtek driver
+      RTL8188FU_Linux_v4.3.23.6_20964.20170110
+      Firmware was embedded in the driver as data statements. This info
+      has been extracted into a binary file.
+File: rtlwifi/rtl8188fufw.bin
+
 Licence: Redistributable. See LICENCE.rtlwifi_firmware.txt for details.
 
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