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>
diff --git a/src/soc/intel/apollolake/Kconfig b/src/soc/intel/apollolake/Kconfig
index 8170942..1872ed0 100644
--- a/src/soc/intel/apollolake/Kconfig
+++ b/src/soc/intel/apollolake/Kconfig
@@ -104,7 +104,8 @@
 	select PLATFORM_USES_FSP2_0
 	select UDK_2015_BINDING if !SOC_INTEL_GLK
 	select UDK_2017_BINDING if SOC_INTEL_GLK
-	select HAVE_HARD_RESET
+	select SOC_INTEL_COMMON_RESET
+	select HAVE_CF9_RESET_PREPARE
 	select INTEL_GMA_ADD_VBT if RUN_FSP_GOP
 	select HAVE_FSP_GOP
 	select NO_UART_ON_SUPERIO
@@ -130,10 +131,6 @@
 	 TPM part is conntected on Fast SPI interface, but the LPC MMIO
 	 TPM transactions are decoded and serialized over the SPI interface.
 
-config SOC_INTEL_COMMON_RESET
-	bool
-	default y
-
 config PCR_BASE_ADDRESS
 	hex
 	default 0xd0000000