ide: constify struct ide_port_info

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/rz1000.c b/drivers/ide/pci/rz1000.c
index 190af15..6b10ae2 100644
--- a/drivers/ide/pci/rz1000.c
+++ b/drivers/ide/pci/rz1000.c
@@ -49,7 +49,7 @@
 	}
 }
 
-static struct ide_port_info rz1000_chipset __devinitdata = {
+static const struct ide_port_info rz1000_chipset __devinitdata = {
 	.name		= "RZ100x",
 	.init_hwif	= init_hwif_rz1000,
 	.chipset	= ide_rz1000,