intel SMI handlers: Refactor GPI SMI/SCI routing

Move the GPI interrupt routing selection between SMI/SCI from
mainboards to southbridge. There is speculation if this is all
just legacy APM stuff that could be removed with a followup.

Change-Id: Iab14cf347584513793f417febc47f0559e17f5a5
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Signed-off-by: Nicolas Reinecke <nr@das-labor.org>
Reviewed-on: http://review.coreboot.org/7967
Tested-by: build bot (Jenkins)
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>
diff --git a/src/southbridge/intel/bd82x6x/pch.h b/src/southbridge/intel/bd82x6x/pch.h
index 4ec2903..a76bf36 100644
--- a/src/southbridge/intel/bd82x6x/pch.h
+++ b/src/southbridge/intel/bd82x6x/pch.h
@@ -70,6 +70,7 @@
 int pch_silicon_type(void);
 int pch_silicon_supported(int type, int rev);
 void pch_iobp_update(u32 address, u32 andvalue, u32 orvalue);
+void gpi_route_interrupt(u8 gpi, u8 mode);
 #if CONFIG_ELOG
 void pch_log_state(void);
 #endif
@@ -146,7 +147,12 @@
 #define BIOS_CNTL		0xDC
 #define GPIO_BASE		0x48 /* LPC GPIO Base Address Register */
 #define GPIO_CNTL		0x4C /* LPC GPIO Control Register */
+
 #define GPIO_ROUT		0xb8
+#define   GPI_DISABLE		0x00
+#define   GPI_IS_SMI		0x01
+#define   GPI_IS_SCI		0x02
+#define   GPI_IS_NMI		0x03
 
 #define PIRQA_ROUT		0x60
 #define PIRQB_ROUT		0x61