drm/i915: s/mdelay/msleep/

Burning cpu cycles isn't awesome, so use sleeps instead.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 99bf147..737e939 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1026,7 +1026,7 @@
 		line_mask = DSL_LINEMASK_GEN3;
 
 	line1 = I915_READ(reg) & line_mask;
-	mdelay(5);
+	msleep(5);
 	line2 = I915_READ(reg) & line_mask;
 
 	return line1 == line2;