fixup! ARM: local timers: Add A15 architected timer support

Add support for the A15 generic timer and clocksource.
As the timer generates interrupts on a different PPI depending
on the execution mode (normal or secure), it is possible to
register two different PPIs.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm/kernel/arch_timer.c

diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index d05a053..95dba02 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -146,6 +146,8 @@
 					0xf, 0x7fffffff);
 
 	enable_percpu_irq(clk->irq, 0);
+	if (arch_timer_ppi2 >= -1)
+		enable_percpu_irq(arch_timer_ppi2, 0);
 }
 
 /* Is the optional system timer available? */