ARM: at91: Add Special Function Registers binding documentation

The special function registers gather some registers that allow to tweak
features provided by IPs controlled through another register range.

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>
1 file changed