CRISv32: annotate irq enable in idle loop

Use a call to local_irq_enable() instead of incline asm so that the
irqsoff latency tracer knows that interrupts are enabled here.
Signed-off-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NJesper Nilsson <jesper.nilsson@axis.com>

arch/cris/arch-v32/kernel/process.c

@@ -23,9 +23,9 @@ extern void stop_watchdog(void);
 /* We use this if we don't have any better idle routine. */
 void default_idle(void)
 {
+	local_irq_enable();
 	/* Halt until exception. */
-	__asm__ volatile("ei    \n\t"
-			 "halt      ");
+	__asm__ volatile("halt");
 }
 
 /*