CONFIG_ARCH_TEGRA_3x_SOC is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Enable support for Tegra30 family

modulename: board-dt-tegra30.ko

and/or

tegra30_clocks.ko

configname: CONFIG_ARCH_TEGRA_3x_SOC

Linux Kernel Configuration
└─>Enable support for Tegra30 family
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Support for NVIDIA Tegra T30 processor family, based on the
ARM CortexA9MP CPU and the ARM PL310 L2 cache controller

source code:
arch/arm/mach-tegra/board-dt-tegra30.c