drm/i915: Fix transposed arguments to skl_plane_wm_level()

Accidentally transposed the arguments to skl_plane_wm_level()
which is causing us to mistakenly think that the plane watermarks
have/have not changed when the opposite may be true. Swap the
arguments so this actually works.

The other uses of this look OK.

Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Fixes: 2871b2f ("drm/i915: Fix TGL+ plane SAGV watermark programming")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325004415.17432-1-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>

drivers/gpu/drm/i915/intel_pm.c

@@ -6017,8 +6017,8 @@ static bool skl_plane_selected_wm_equals(struct intel_plane *plane,
 		 * use it. It only gets used for calculating the required
 		 * ddb allocation.
 		 */
-		if (!skl_wm_level_equals(skl_plane_wm_level(old_pipe_wm, level, plane->id),
-					 skl_plane_wm_level(new_pipe_wm, level, plane->id)))
+		if (!skl_wm_level_equals(skl_plane_wm_level(old_pipe_wm, plane->id, level),
+					 skl_plane_wm_level(new_pipe_wm, plane->id, level)))
 			return false;
 	}