mb/intel/dg43gt: Fix smbus IRQ

This board uses the reset defaults for DxxIP and DxxIR.
The datasheet "Intel ® I/O Controller Hub 10 (ICH10) Family"
mistakenly says in the D31IP register that all function have INTB as
default. This is however not true as documented in the reset default
value.

This fixes the DSDT such that the SMBus device gets a route for the
INT C interrupt it uses.

Change-Id: I3dd1308fb7acec86b90ecd9d2079cf9a58702c40
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/21442
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/intel/dg43gt/acpi/x4x_pci_irqs.asl

@@ -52,6 +52,8 @@ Method(_PRT)
 			Package() { 0x001dffff, 3, 0, 0x13 },
 			/* SMBUS/SATA/PATA	0:1f.2, 0:1f.3 */
 			Package() { 0x001fffff, 1, 0, 0x11 },
+			Package() { 0x001fffff, 2, 0, 0x12 },
+			Package() { 0x001fffff, 3, 0, 0x13 },
 		})
 	} Else {
 		Return (Package() {
@@ -86,6 +88,8 @@ Method(_PRT)
 			Package() { 0x001dffff, 3, \_SB.PCI0.LPCB.LNKD, 0 },
 			/* PATA/SATA/SMBUS		0:1f.1-3 */
 			Package() { 0x001fffff, 1, \_SB.PCI0.LPCB.LNKB, 0 },
+			Package() { 0x001fffff, 2, \_SB.PCI0.LPCB.LNKC, 0 },
+			Package() { 0x001fffff, 3, \_SB.PCI0.LPCB.LNKD, 0 },
 		})
 	}
 }