Add Intel C216 chipset PCI support.

Reference: /n/sources/patch/applied/pci-c216
Date: Thu Apr 11 22:29:27 CES 2013
Signed-off-by: djc@9grid.fr

--- /sys/src/9/pc/pci.c	Thu Apr 11 22:29:13 2013
+++ /sys/src/9/pc/pci.c	Thu Apr 11 22:29:07 2013
@@ -668,6 +668,7 @@
 	{ 0x8086, 0x3a48, pIIxget, pIIxset },	/* Intel 82801JI */
 	{ 0x8086, 0x2916, pIIxget, pIIxset },	/* Intel 82801? */
 	{ 0x8086, 0x1c02, pIIxget, pIIxset },	/* Intel 6 Series/C200 */
+	{ 0x8086, 0x1e53, pIIxget, pIIxset },	/* Intel 7 Series/C216 */
 	{ 0x1106, 0x0586, viaget, viaset },	/* Viatech 82C586 */
 	{ 0x1106, 0x0596, viaget, viaset },	/* Viatech 82C596 */
 	{ 0x1106, 0x0686, viaget, viaset },	/* Viatech 82C686 */