samples: Simplify ESP32 overlays moving to socs

Move overlays and conf from boards to socs in following samples :

- samples/drivers/adc/adc_dt
- samples/drivers/counter/alarm
- samples/drivers/dac
- samples/subsys/settings

Signed-off-by: Marek Matej <marek.matej@espressif.com>

add more samples

Signed-off-by: Marek Matej <marek.matej@espressif.com>