clk: imx35: 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: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/clk/imx/clk-imx35.c

@@ -84,6 +84,14 @@ enum mx35_clks {
 
 static struct clk *clk[clk_max];
 
+static struct clk ** const uart_clks[] __initconst = {
+	&clk[ipg],
+	&clk[uart1_gate],
+	&clk[uart2_gate],
+	&clk[uart3_gate],
+	NULL
+};
+
 static void __init _mx35_clocks_init(void)
 {
 	void __iomem *base;
@@ -237,6 +245,8 @@ static void __init _mx35_clocks_init(void)
 	 */
 	clk_prepare_enable(clk[scc_gate]);
 
+	imx_register_uart_clocks(uart_clks);
+
 	imx_print_silicon_rev("i.MX35", mx35_revision());
 }