Realtek SMI interface support

configname: CONFIG_NET_DSA_REALTEK_SMI

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Distributed Switch Architecture drivers
└─>Realtek Ethernet switch family support
└─>Device Tree and Open Firmware support
└─>Realtek SMI interface support
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Select to enable support for registering switches connected
through SMI.