ADSP: don't use timer interrupts on secondary cores

When running SOF on Intel ADSP we choose to only serve the timer
interrupt on the primary core.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

drivers/timer/intel_adsp_timer.c

@@ -210,7 +210,6 @@ static void irq_init(void)
 
 void smp_timer_init(void)
 {
-	irq_init();
 }
 
 /* Runs on core 0 only */