enable ETNAVIV thermal throttling

configname: CONFIG_DRM_ETNAVIV_THERMAL

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>enable ETNAVIV thermal throttling
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Compile in support for thermal throttling.
Say Y unless you want to risk burning your SoC.