Input: drv260x/drv2665/drv2667 - constify reg_default tables

These reg_default tables are not modified after initialized, so make them
const.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/misc/drv2667.c b/drivers/input/misc/drv2667.c
index fc0fddf..a231342 100644
--- a/drivers/input/misc/drv2667.c
+++ b/drivers/input/misc/drv2667.c
@@ -116,7 +116,7 @@
 	u32 frequency;
 };
 
-static struct reg_default drv2667_reg_defs[] = {
+static const struct reg_default drv2667_reg_defs[] = {
 	{ DRV2667_STATUS, 0x02 },
 	{ DRV2667_CTRL_1, 0x28 },
 	{ DRV2667_CTRL_2, 0x40 },