boards: hifive1: Add missing board yaml file
boards: hifive1: Add missing board yaml file

When we added support for the HiFive1 board we forget to make sure it
had a board yaml file.  Add the file so we get sanitycheck running on
the board.

Signed-off-by: Kumar Gala <a5e5248af4cd4f0ed8c515f61d40a6e2db46a66e@linaro.org>

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