drm/i915/gvt: Fix typo of VBLANK_TIMER_PERIOD

This fixes typo for VBLANK_TIMER_PERIOD.
Reviewed-by: NXiong Zhang <xiong.y.zhang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/interrupt.c

@@ -672,7 +672,7 @@ void intel_gvt_clean_irq(struct intel_gvt *gvt)
 	hrtimer_cancel(&irq->vblank_timer.timer);
 }
 
-#define VBLNAK_TIMER_PERIOD 16000000
+#define VBLANK_TIMER_PERIOD 16000000
 
 /**
  * intel_gvt_init_irq - initialize GVT-g IRQ emulation subsystem
@@ -704,7 +704,7 @@ int intel_gvt_init_irq(struct intel_gvt *gvt)
 
 	hrtimer_init(&vblank_timer->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
 	vblank_timer->timer.function = vblank_timer_fn;
-	vblank_timer->period = VBLNAK_TIMER_PERIOD;
+	vblank_timer->period = VBLANK_TIMER_PERIOD;
 
 	return 0;
 }