rtl_bt: Update firmware for BT part of RTL8822C

The file was sent to me by Max Chou <max.chou@realtek.com>.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Max Chou <max.chou@realtek.com>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>

WHENCE

@@ -3254,6 +3254,8 @@ Files rtl_bt/rtl8822b_* came directly from Realtek. These files are
 updated on April 14, 2017.
 Files rtl_bt/rtl8821c_* and rtl_bt/rtl8723d_* came directly from Realtek.
 File rtl_bt/rtl8822cu_fw.bin came directly from Realtek.
+updated on February 24, 2019
+File rtl_bt/rtl8822cu_fw.bin came directly from Realtek.
 
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