ARM: at91: add support in soc driver for new SAM9X60

Add detection of new SAM9X60 by this soc.c driver.

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[nicolas.ferre@microchip.com: split patch]
Signed-off-by: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>