commit d3df1ec0 upstream.

Remove ADC channels that are not available by default on the sama5d3_xplained
board (resistor not populated) in order to not create confusion.
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>