clk: imx: get stdout clk count from device tree

Currently the clk_count is specified by API users, but this
parameter is wrongly used, for example, i.MX8M clk driver use 4,
however the uart device tree node only use 2 clock entries. So
let using of_clk_get_parent_count to get the exact clock count.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/20230104110032.1220721-3-peng.fan@oss.nxp.com

drivers/clk/imx/clk.c

@@ -167,6 +167,8 @@ __setup_param("earlyprintk", imx_keep_uart_earlyprintk,
 
 void imx_register_uart_clocks(unsigned int clk_count)
 {
+	unsigned int num __maybe_unused;
+
 	imx_enabled_uart_clocks = 0;
 
 /* i.MX boards use device trees now.  For build tests without CONFIG_OF, do nothing */
@@ -174,14 +176,18 @@ void imx_register_uart_clocks(unsigned int clk_count)
 	if (imx_keep_uart_clocks) {
 		int i;
 
-		imx_uart_clocks = kcalloc(clk_count, sizeof(struct clk *), GFP_KERNEL);
-		if (!imx_uart_clocks)
+		num = of_clk_get_parent_count(of_stdout);
+		if (!num)
 			return;
 
 		if (!of_stdout)
 			return;
 
-		for (i = 0; i < clk_count; i++) {
+		imx_uart_clocks = kcalloc(num, sizeof(struct clk *), GFP_KERNEL);
+		if (!imx_uart_clocks)
+			return;
+
+		for (i = 0; i < num; i++) {
 			imx_uart_clocks[imx_enabled_uart_clocks] = of_clk_get(of_stdout, i);
 
 			/* Stop if there are no more of_stdout references */