rtc: at91sam9: include linux/of.h
rtc: at91sam9: include linux/of.h

This driver is using device tree but is not including of.h

Signed-off-by: Alexandre Belloni <a7228e626ecf0022ac91fc1cd8db88e71d0e5e0e@free-electrons.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs