intel: Use CF9 reset (part 2)

Make use of the common CF9 reset in SOC_INTEL_COMMON_RESET. Also
implement board_reset() as a "full reset" (aka. cold reset) as that
is what was used here for hard_reset().

Drop soc_reset_prepare() thereby, as it was only used for APL. Also,
move the global-reset logic.

We leave some comments to remind us that a system_reset() should
be enough, where a full_reset() is called now (to retain current
behaviour) and looks suspicious.

Note, as no global_reset() is implemented for Denverton-NS, we halt
there now instead of issuing a non-global reset. This seems safer;
a non-global reset might result in a reset loop.

Change-Id: I5e7025c3c9ea6ded18e72037412b60a1df31bd53
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/29169
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/cpu/intel/reset.h

@@ -1,26 +0,0 @@
-/*
- * This file is part of the coreboot project.
- *
- * Copyright (C) 2017 Intel Corp.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-#ifndef CPU_INTEL_RESET_H
-#define CPU_INTEL_RESET_H
-
-/* Reset control port */
-#define RST_CNT			0xcf9
-#define FULL_RST		(1 << 3)
-#define RST_CPU			(1 << 2)
-#define SYS_RST			(1 << 1)
-
-#endif	/* CPU_INTEL_RESET_H */