mb,sb,soc/intel: Drop useless IO trap handlers

There are four requirements for the SMI to hit a printk()
this commit now removes.

Build must have DEBUG_SMI=y, otherwise any printk() is a no-op
inside SMM.
ASL must have a TRAP() with argument 0x99 or 0x32 for SMIF value.
Platform needs to have IO Trap #3 enabled at IO 0x800.
The SMI monitor must call io_trap_handler for IO Trap #3.

At the moment, only getac/p470 would meet the above criteria
with TRAP(0x32) in its DSDT _INI method. The ASL ignores any
return value of TRAP() calls made.

A mainboard IO trap handler should have precedence over
a southbridge IO trap handler. At the moment we seem to have
no cases of the latter to support, so remove the latter.

Change-Id: I3a3298c8d9814db8464fbf7444c6e0e6ac6ac008
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70365
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/mainboard/intel/kunimitsu/smihandler.c

@@ -4,32 +4,11 @@
 #include <cpu/x86/smm.h>
 #include <ec/google/chromeec/smm.h>
 #include <soc/iomap.h>
-#include <soc/nvs.h>
 #include <soc/pm.h>
 #include <intelblocks/smihandler.h>
 #include "ec.h"
 #include "gpio.h"
 
-int mainboard_io_trap_handler(int smif)
-{
-	switch (smif) {
-	case 0x99:
-		printk(BIOS_DEBUG, "Sample\n");
-		gnvs->smif = 0;
-		break;
-	default:
-		return 0;
-	}
-
-	/* On success, the IO Trap Handler returns 0
-	 * On failure, the IO Trap Handler returns a value != 0
-	 *
-	 * For now, we force the return value to 0 and log all traps to
-	 * see what's going on.
-	 */
-	return 1;
-}
-
 void mainboard_smi_gpi_handler(const struct gpi_status *sts)
 {
 	if (gpi_status_get(sts, EC_SMI_GPI))