intel_idle: use pr_info() instead of printk()

Substitute 'printk()' with 'pr_info()', because 'intel_idle' already uses
'pr_debug()', so using 'pr_info()' will be more consistent.

In addition to this, this patch addresses  the following checkpatch.pl
warning:
  WARNING: printk() should include KERN_<LEVEL> facility level
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/idle/intel_idle.c

@@ -1895,7 +1895,7 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
 		drv->states[drv->state_count] = cpuidle_state_table[cstate];
 
 		if ((cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IRQ_ENABLE) || force_irq_on) {
-			printk("intel_idle: forced intel_idle_irq for state %d\n", cstate);
+			pr_info("forced intel_idle_irq for state %d\n", cstate);
 			drv->states[drv->state_count].enter = intel_idle_irq;
 		}