Staging: rtl8812ae: Add Realtek 8821 PCI WIFI driver

This comes directly from the Realtek tarball, filename:
	wifi_driver_8821ae_0018.1129.2013.tar.gz

I mushed the three modules (btcoexist, rtlwifi and rtl8821ae) together
into one, in order to make it all build as one stand-alone module.
After the btcoexist driver gets merged upstream, I'll pull it out of
here, and will continue to work on removing this version of rtlwifi in
order to use the in-kernel one.

Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>