clk: renesas: Tear clock controller down last before booting OS

Once all the other drivers got torn down in preparation for the OS
to start, tear down the clock controller last. The clock controller
must be torn down last as some of the clock which get turned off
might have still been needed during the teardown stage of the other
drivers.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Signed-off-by: Tam Nguyen <tam.nguyen.xa@renesas.com>
Signed-off-by: Hai Pham <hai.pham.ud@renesas.com>
diff --git a/drivers/clk/renesas/clk-rcar-gen3.c b/drivers/clk/renesas/clk-rcar-gen3.c
index c8a5512..0d274bb 100644
--- a/drivers/clk/renesas/clk-rcar-gen3.c
+++ b/drivers/clk/renesas/clk-rcar-gen3.c
@@ -526,6 +526,7 @@
 	.ops		= &gen3_clk_ops,
 	.probe		= gen3_clk_probe,
 	.remove		= gen3_clk_remove,
+	.flags          = DM_FLAG_OS_PREPARE | DM_FLAG_VITAL,
 };
 
 static int gen3_reset_assert(struct reset_ctl *reset_ctl)
@@ -565,6 +566,7 @@
 	.name = "rst_gen3",
 	.id = UCLASS_RESET,
 	.ops = &rst_gen3_ops,
+	.flags = DM_FLAG_OS_PREPARE | DM_FLAG_VITAL,
 };
 
 int gen3_cpg_bind(struct udevice *parent)