arm: imx8ulp: add clock support

Add i.MX8ULP clock support

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/mach-imx/imx8ulp/soc.c b/arch/arm/mach-imx/imx8ulp/soc.c
index 3029589..6f4b506 100644
--- a/arch/arm/mach-imx/imx8ulp/soc.c
+++ b/arch/arm/mach-imx/imx8ulp/soc.c
@@ -287,5 +287,8 @@
 
 int arch_cpu_init(void)
 {
+	if (IS_ENABLED(CONFIG_SPL_BUILD))
+		clock_init();
+
 	return 0;
 }