rtlwifi: btcoex: 23b 1ant: rename and coding style modification.

Rename:
 * tdma_adj_type to ps_tdma_du_adj_type
 * wifiCentralChnl to wifi_central_chnl

Coding style:
 * move constant from right to left side in if-statement

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: Kalle Valo <kvalo@codeaurora.org>