clk: imx6ul: retain early UART clocks during kernel init

Make sure to keep UART clocks enabled during kernel init if
earlyprintk or earlycon are active.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20230421115517.1940990-1-alexander.stein@ew.tq-group.com
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>

Author: tq-steina

drivers/clk/imx/clk-imx6ul.c

@@ -544,6 +544,8 @@ static void __init imx6ul_clocks_init(struct device_node *ccm_node)
 
 	clk_set_parent(hws[IMX6UL_CLK_ENET1_REF_SEL]->clk, hws[IMX6UL_CLK_ENET_REF]->clk);
 	clk_set_parent(hws[IMX6UL_CLK_ENET2_REF_SEL]->clk, hws[IMX6UL_CLK_ENET2_REF]->clk);
+
+	imx_register_uart_clocks();
 }
 
 CLK_OF_DECLARE(imx6ul, "fsl,imx6ul-ccm", imx6ul_clocks_init);