cpu/saml21: define ADC pins
cpu/saml21: define ADC pins

kaspar030/RIOT,RIOT-OS/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,jasonatran/RIOT,jasonatran/RIOT,ant9000/RIOT,ant9000/RIOT,kaspar030/RIOT,jasonatran/RIOT,jasonatran/RIOT,miri64/RIOT,ant9000/RIOT,miri64/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,miri64/RIOT,RIOT-OS/RIOT,kaspar030/RIOT,ant9000/RIOT,ant9000/RIOT,RIOT-OS/RIOT,miri64/RIOT,miri64/RIOT,kaspar030/RIOT