usb: amd5536udc: Fix the type of ep_string

Use "static const char *const" instead of "static const char *".

Signed-off-by: Cyril Roelandt <tipecaml@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/amd5536udc.c b/drivers/usb/gadget/amd5536udc.c
index d28bc24..9349c4e 100644
--- a/drivers/usb/gadget/amd5536udc.c
+++ b/drivers/usb/gadget/amd5536udc.c
@@ -140,7 +140,7 @@
 
 /* endpoint names used for print */
 static const char ep0_string[] = "ep0in";
-static const char *ep_string[] = {
+static const char *const ep_string[] = {
 	ep0_string,
 	"ep1in-int", "ep2in-bulk", "ep3in-bulk", "ep4in-bulk", "ep5in-bulk",
 	"ep6in-bulk", "ep7in-bulk", "ep8in-bulk", "ep9in-bulk", "ep10in-bulk",