ARM: dts: at91: sama5d27_som1_ek: add disabled status

Add disabled statuses for all devices and for those those which pins
are in conflict with other devices add a comment in the DT file to specify
this.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>