arm: npcm: add basic support for Nuvoton BMCs

Adds basic support for the Nuvoton NPCM750 BMC.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Tomer Maimon <tmaimon77@gmail.com>
Reviewed-by: Avi Fishman <avifishman70@gmail.com>
Tested-by: Tomer Maimon <tmaimon77@gmail.com>
Tested-by: Avi Fishman <avifishman70@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-npcm/headsmp.S

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Nuvoton Technology corporation.
+// Copyright 2018 Google, Inc.
+
+#include <linux/linkage.h>
+#include <linux/init.h>
+#include <asm/assembler.h>
+
+/*
+ * The boot ROM does not start secondary CPUs in SVC mode, so we need to do that
+ * here.
+ */
+ENTRY(npcm7xx_secondary_startup)
+	safe_svcmode_maskall r0
+
+	b	secondary_startup
+ENDPROC(npcm7xx_secondary_startup)