Add Intel C226 chipset PCI support.

Reference: /n/sources/patch/pci-c226
Date: Wed Jul  9 20:32:30 CES 2014
Signed-off-by: djc@9grid.fr

--- /sys/src/9/pc/pci.c	Wed Jul  9 20:32:13 2014
+++ /sys/src/9/pc/pci.c	Wed Jul  9 20:32:03 2014
@@ -670,6 +670,7 @@
 	{ 0x8086, 0x1c02, pIIxget, pIIxset },	/* Intel 6 Series/C200 */
 	{ 0x8086, 0x1c44, pIIxget, pIIxset },	/* Intel 6 Series/Z68 Express */
 	{ 0x8086, 0x1e53, pIIxget, pIIxset },	/* Intel 7 Series/C216 */
+	{ 0x8086, 0x8c56, pIIxget, pIIxset },	/* Intel 8 Series/C226 */
 	{ 0x1106, 0x0586, viaget, viaset },	/* Viatech 82C586 */
 	{ 0x1106, 0x0596, viaget, viaset },	/* Viatech 82C596 */
 	{ 0x1106, 0x0686, viaget, viaset },	/* Viatech 82C686 */