armv7R: K3: am654: Trigger panic on DDR init failures

When initializing DDR from R5 SPL trigger U-Boot's panic facility
rather than simply returning from the board init function as there
is little point continuing code execution. Further, as panic implies
a board reset, so using it might potentially allow to recover from
this error in certain cases such as when the init failure was caused
by a temporary glitch of some sorts.

Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Reviewed-by: Lokesh Vutla <lokeshvutla@ti.com>

arch/arm/mach-k3/am6_init.c

@@ -83,10 +83,8 @@ void board_init_f(ulong dummy)
 
 #ifdef CONFIG_K3_AM654_DDRSS
 	ret = uclass_get_device(UCLASS_RAM, 0, &dev);
-	if (ret) {
-		printf("DRAM init failed: %d\n", ret);
-		return;
-	}
+	if (ret)
+		panic("DRAM init failed: %d\n", ret);
 #endif
 }