Realtek protocol support

configname: CONFIG_BT_HCIUART_RTL

Linux Kernel Configuration
└─>Networking support
└─>Bluetooth subsystem support
└─>Bluetooth device drivers
└─>Realtek protocol support
In linux kernel since version 4.2 (release Date: 2015-08-30)  
The Realtek protocol support enables Bluetooth HCI over 3-Wire
serial port interface for Realtek Bluetooth controllers.

Say Y here to compile support for Realtek protocol.