ARM: at91: sama5d4: Add SFR

The sama4d4 has Special Function Registers that allow to manage DDR, OHCI, EBI
and AIC interrupt redirection.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[nicolas.ferre@atmel.com: reg size: 0x60]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>