CONFIG_DT_BCM93384WVG_VIPER is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

BCM93384WVG Viper CPU (EXPERIMENTAL)

configname: CONFIG_DT_BCM93384WVG_VIPER

Built-in device tree
└─>BCM93384WVG Viper CPU (EXPERIMENTAL)
In linux kernel since version 4.1 (release Date: 2015-06-21)