boards: stm32f3_disco: Add usb_device to supported features
boards: stm32f3_disco: Add usb_device to supported features

Add usb_device in board's metadata yaml file.

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

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