stm32mp1: spl: hang with trace when DDR init failed

When DDR initialization failed, print error message
and stop the SPL execution.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/arch/arm/mach-stm32mp/spl.c b/arch/arm/mach-stm32mp/spl.c
index 501e077..a3b0d6f 100644
--- a/arch/arm/mach-stm32mp/spl.c
+++ b/arch/arm/mach-stm32mp/spl.c
@@ -111,7 +111,7 @@
 
 	ret = uclass_get_device(UCLASS_RAM, 0, &dev);
 	if (ret) {
-		debug("DRAM init failed: %d\n", ret);
-		return;
+		printf("DRAM init failed: %d\n", ret);
+		hang();
 	}
 }