rtlwifi: rtl8192ce: rtl8192de: rtl8192se: Fix handling for missing get_btc_status

The recent changes in checking for Bluetooth status added some callbacks to code
in rtlwifi. To make certain that all callbacks are defined, a dummy routine has been
added to rtlwifi, and the drivers that need to use it are modified.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Murilo Opsfelder Araujo <mopsfelder@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>