Atheros DFS support for certified platforms

configname: CONFIG_ATH9K_DFS_CERTIFIED

Linux Kernel Configuration
└─>Device Drivers
└─>Network device support
└─>Wireless LAN
└─>Atheros DFS support for certified platforms
In linux kernel since version 3.1 (release Date: 2011-10-24)  
This option enables DFS support for initiating radiation on
ath9k. There is no way to dynamically detect if a card was DFS
certified and as such this is left as a build time option. This
option should only be enabled by system integrators that can
guarantee that all the platforms that their kernel will run on
have obtained appropriate regulatory body certification for a
respective Atheros card by using ath9k on the target shipping
platforms.

This is currently only a placeholder for future DFS support,
as DFS support requires more components that still need to be
developed. At this point enabling this option won't do anything
except increase code size.