boards: efm32wg_stk3800: Fix boards dts file copyright
boards: efm32wg_stk3800: Fix boards dts file copyright

Christian Taedcke is the author of this file according to
PR #271.

Signed-off-by: Yannis Damigos <bda985a2727ac24c41652a294292988d6fc7dc73@gmail.com>

zephyriot/zephyr,Vudentz/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,kraj/zephyr,finikorg/zephyr,zephyriot/zephyr,nashif/zephyr,Vudentz/zephyr,punitvara/zephyr,kraj/zephyr,nashif/zephyr,galak/zephyr,zephyriot/zephyr,ldts/zephyr,explora26/zephyr,kraj/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,kraj/zephyr,zephyriot/zephyr,punitvara/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,punitvara/zephyr,nashif/zephyr,punitvara/zephyr,ldts/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,Vudentz/zephyr,galak/zephyr,GiulianoFranchetto/zephyr,mbolivar/zephyr,galak/zephyr,ldts/zephyr,galak/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr,mbolivar/zephyr,nashif/zephyr,punitvara/zephyr,galak/zephyr,Vudentz/zephyr,zephyriot/zephyr,finikorg/zephyr,mbolivar/zephyr,GiulianoFranchetto/zephyr,mbolivar/zephyr,explora26/zephyr,explora26/zephyr,ldts/zephyr,explora26/zephyr,finikorg/zephyr,mbolivar/zephyr,zephyrproject-rtos/zephyr