pata_it821x: use "const char *" for string literals

Some string literals are pointed to by "char *".  This patch fixes
that.

tj: Updated patch title and description.
Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/pata_it821x.c

@@ -604,9 +604,9 @@ static void it821x_display_disk(int n, u8 *buf)
 {
 	unsigned char id[41];
 	int mode = 0;
-	char *mtype = "";
+	const char *mtype = "";
 	char mbuf[8];
-	char *cbl = "(40 wire cable)";
+	const char *cbl = "(40 wire cable)";
 
 	static const char *types[5] = {
 		"RAID0", "RAID1", "RAID 0+1", "JBOD", "DISK"
@@ -903,7 +903,7 @@ static int it821x_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
 	};
 
 	const struct ata_port_info *ppi[] = { NULL, NULL };
-	static char *mode[2] = { "pass through", "smart" };
+	static const char *mode[2] = { "pass through", "smart" };
 	int rc;
 
 	rc = pcim_enable_device(pdev);