staging: r8822be: Add the driver code

The RTL8822BE, an 802.11ac wireless network card, is now appearing in
new computers. Its driver is being placed in staging to reduce the time
that users of this new card will have access to in-kernel drivers.

This commit adds the code for the new r8822be driver.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Yan-Hsuan Chuang <yhchuang@realtek.com>
Cc: Birming Chiu <birming@realtek.com>
Cc: Shaofu <shaofu@realtek.com>
Cc: Steven Ting <steventing@realtek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>