net: Add non-mainline source for rtl8192cu wlan

Add non-mainline source for rtl8192cu wireless driver version v4.0.2_9000 as
this is widely used. Disable older rtlwifi driver.

8192cu needs old wireless extensions

The obsolete WIRELESS_EXT configuration is used
by the old Realtek code and is needed for AP support.

8192cu: CONFIG_AP_MODE hardcoded in autoconf.h

rtl8192c_rf6052: PHY_RFShadowRefresh(): fix off-by-one

Signed-off-by: Marc Kleine-Budde <mkl@blackshift.org>

rtl8192cu: Add PID for D-Link DWA 131