rtlwifi: btcoex: 21a 1ant: add function to check wifi status

rtlwifi: btcoex: 21a 1ant: add function to check wifi status

This function checks if wifi has changed its statusi. It will be needed
in the future.

Signed-off-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Pkshih <pkshih@realtek.com>
Cc: Birming Chiu <birming@realtek.com>
Cc: Shaofu <shaofu@realtek.com>
Cc: Steven Ting <steventing@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>