ide: constify struct ide_port_info

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/siimage.c b/drivers/ide/pci/siimage.c
index f066bc5..dc915cb 100644
--- a/drivers/ide/pci/siimage.c
+++ b/drivers/ide/pci/siimage.c
@@ -905,7 +905,7 @@
 		.udma_mask	= ATA_UDMA6,		\
 	}
 
-static struct ide_port_info siimage_chipsets[] __devinitdata = {
+static const struct ide_port_info siimage_chipsets[] __devinitdata = {
 	/* 0 */ DECLARE_SII_DEV("SiI680"),
 	/* 1 */ DECLARE_SII_DEV("SiI3112 Serial ATA"),
 	/* 2 */ DECLARE_SII_DEV("Adaptec AAR-1210SA")