tests/drivers: adc: add config for NXP Freedom K22F board
tests/drivers: adc: add config for NXP Freedom K22F board

Add the configuration block for NXP Freedom K22F board for
the adc_api test.

Signed-off-by: Sean Nyekjaer <f3d9424b5a4f30ffa2137b981e89ac7f33ab5a19@prevas.dk>

nashif/zephyr,nashif/zephyr,Vudentz/zephyr,galak/zephyr,galak/zephyr,nashif/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,Vudentz/zephyr,Vudentz/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr