ARM: dts: at91: at91-sama5d27_som1: add sama5d27 SoM1 support

Add specific DTS file and bindings for sama5d27 SoM1 board.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>