staging: rtl8723bs: remove the repeated declaration

staging: rtl8723bs: remove the repeated declaration

Function 'rtw_indicate_wx_disassoc_event' and 'Hal_SetBandwidth' are
declared twice in their header file, so remove the repeated declaration.

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Link: https://lore.kernel.org/r/1622077092-50618-1-git-send-email-zhangshaokun@hisilicon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>