ARM: 7674/1: smp: Avoid dummy clockevent being preferred over real hardware clock-event

With recent arm broadcast time clean-up from Mark Rutland, the dummy
broadcast device is always registered with timer subsystem. And since
the rating of the dummy clock event is very high, it may be preferred
over a real clock event.

This is a change in behavior from past and not an intended one. So
reduce the rating of the dummy clock-event so that real clock-event
device is selected when available.

Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>