boards: nucleo_l432kc: mark nvs sample as supported
boards: nucleo_l432kc: mark nvs sample as supported

Now that the corresponding flash definitions have been added to the DTS,
it's possible to enable the nvs sample in the NUCLEO-L432KC board.

Signed-off-by: Aurelien Jarno <bceb368e7f2cb351af47298f32034f0587bbe4a6@aurel32.net>

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