Enable SATA ports 0 to 5 in sdiahci.

See the "Intel I/O Controller Hub 9 (ICH9) Family Datasheet"
document, section 14.1.31, "PCS Port Control and Status Register".

http://www.intel.com/content/dam/doc/datasheet/io-controller-hub-9-datasheet.pdf

Reference: /n/sources/patch/applied/sdiahci-iaahcimode-ports
Date: Wed Jun  6 17:41:34 CES 2012
Signed-off-by: djc@9grid.fr

--- /sys/src/9/pc/sdiahci.c	Wed Jun  6 17:41:19 2012
+++ /sys/src/9/pc/sdiahci.c	Wed Jun  6 17:41:10 2012
@@ -1823,8 +1823,7 @@
 {
 	dprint("iaahcimode: %ux %ux %ux\n", pcicfgr8(p, 0x91), pcicfgr8(p, 92),
 		pcicfgr8(p, 93));
-	pcicfgw16(p, 0x92, pcicfgr32(p, 0x92) | 0xf);	/* ports 0-3 */
-//	pcicfgw8(p, 0x93, pcicfgr32(p, 9x93) | 3);	/* ports 4-5 */
+	pcicfgw16(p, 0x92, pcicfgr16(p, 0x92) | 0xf);	/* ports 0-5 */
 	return 0;
 }