arch/risc-v/src/mpfs/mpfs_start.c: Don't boot if DDR is enabled and training fails

Output "X" with showprogress and make a system reset.

Silently ignoring failed training is dangerous and will cause random behaviour if DDR is used

Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>

arch/risc-v/src/mpfs/mpfs_start.c

@@ -167,7 +167,19 @@ void __mpfs_start(uint64_t mhartid)
 #endif
 
 #ifdef CONFIG_MPFS_DDR_INIT
-  mpfs_ddr_init();
+  if (mpfs_ddr_init() != 0)
+    {
+      /* We don't allow booting, ddr training failure will cause random
+       * behaviour
+       */
+
+      showprogress('X');
+
+      /* Reset, but let the progress come out of the uart first */
+
+      up_udelay(1000);
+      up_systemreset();
+    }
 #endif
 
   showprogress('B');