arm: imx8: factor out uart init code

New imx8 boards started adding duplicated UART init code.
Factor out this to common function sc_pm_setup_uart().

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/board/freescale/imx8qm_mek/imx8qm_mek.c b/board/freescale/imx8qm_mek/imx8qm_mek.c
index e69efc4..249c29e 100644
--- a/board/freescale/imx8qm_mek/imx8qm_mek.c
+++ b/board/freescale/imx8qm_mek/imx8qm_mek.c
@@ -34,21 +34,11 @@
 
 int board_early_init_f(void)
 {
+	sc_pm_clock_rate_t rate = SC_80MHZ;
 	int ret;
-	/* Set UART0 clock root to 80 MHz */
-	sc_pm_clock_rate_t rate = 80000000;
-
-	/* Power up UART0 */
-	ret = sc_pm_set_resource_power_mode(-1, SC_R_UART_0, SC_PM_PW_MODE_ON);
-	if (ret)
-		return ret;
 
-	ret = sc_pm_set_clock_rate(-1, SC_R_UART_0, 2, &rate);
-	if (ret)
-		return ret;
-
-	/* Enable UART0 clock root */
-	ret = sc_pm_clock_enable(-1, SC_R_UART_0, 2, true, false);
+	/* Set UART0 clock root to 80 MHz */
+	ret = sc_pm_setup_uart(SC_R_UART_0, rate);
 	if (ret)
 		return ret;