ARM: multi_v7_defconfig: Add Atmel SAMA5 family

Add the Atmel sama5d3 and sama5d4 and their peripherals to multi_v7_defconfig.

Note that the console will be ttyAT0 instead of the usual ttyS0.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>