fix(a3k): change fatal error to warning when CM3 reset is not implemented

This allows TF-A's a3700_system_reset() function to try Warm reset
method when CM3 reset method is not implemented by WTMI firmware.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I7303197373e1a8ca5a44ba0b1e90b48855d6c0c3
diff --git a/plat/marvell/armada/a3k/common/cm3_system_reset.c b/plat/marvell/armada/a3k/common/cm3_system_reset.c
index 548ff51..f105d59 100644
--- a/plat/marvell/armada/a3k/common/cm3_system_reset.c
+++ b/plat/marvell/armada/a3k/common/cm3_system_reset.c
@@ -58,5 +58,5 @@
 	}
 
 	/* If we reach here, the command is not implemented. */
-	ERROR("System reset command not implemented in WTMI firmware!\n");
+	WARN("System reset command not implemented in WTMI firmware!\n");
 }