drm/i915: Convert wait_for(I915_READ(reg)) to intel_wait_for_register()

By using the out-of-line intel_wait_for_register() not only do we can
efficiency from using the hybrid wait_for() contained within, but we
avoid code bloat from the numerous inlined loops, in total (all patches):

   text    data     bss     dec     hex filename
1078551    4557     416 1083524  108884 drivers/gpu/drm/i915/i915.ko
1070775    4557     416 1075748  106a24 drivers/gpu/drm/i915/i915.ko
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467297225-21379-60-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/intel_uncore.c

@@ -1530,15 +1530,17 @@ static int ironlake_do_reset(struct drm_i915_private *dev_priv,
 
 	I915_WRITE(ILK_GDSR,
 		   ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
-	ret = wait_for((I915_READ(ILK_GDSR) &
-			ILK_GRDOM_RESET_ENABLE) == 0, 500);
+	ret = intel_wait_for_register(dev_priv,
+				      ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0,
+				      500);
 	if (ret)
 		return ret;
 
 	I915_WRITE(ILK_GDSR,
 		   ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
-	ret = wait_for((I915_READ(ILK_GDSR) &
-			ILK_GRDOM_RESET_ENABLE) == 0, 500);
+	ret = intel_wait_for_register(dev_priv,
+				      ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0,
+				      500);
 	if (ret)
 		return ret;