ARM: dt: dove: wire up RTC interrupt

Now that we have a PMU driver, we can wire up the RTC interrupt in the
DT description for Dove.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>