clk: tests: Add reference to the orphan mux bug report

Some more context might be useful for unit-tests covering a previously
reported bug, so let's add a link to the discussion for that bug.

Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> # imx8mp
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> # exynos4210, meson g12b
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220816112530.1837489-8-maxime@cerno.techTested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/clk_test.c

@@ -322,6 +322,9 @@ static void clk_orphan_transparent_single_parent_mux_test_exit(struct kunit *tes
 /*
  * Test that a mux-only clock, with an initial rate within a range,
  * will still have the same rate after the range has been enforced.
+ *
+ * See:
+ * https://lore.kernel.org/linux-clk/7720158d-10a7-a17b-73a4-a8615c9c6d5c@collabora.com/
  */
 static void clk_test_orphan_transparent_parent_mux_set_range(struct kunit *test)
 {