Input: constify device_type structures

Declare device_type structures as const as they are only stored in the
type field of a device structure. This field is of type const, so add
const to declaration of device_type structures.

File size before:
   text	   data	    bss	    dec	    hex	filename
  17184	   1344	     80	  18608	   48b0	drivers/input/input.o

File size after:
   text	   data	    bss	    dec	    hex	filename
  17248	   1280	     80	  18608	   48b0	drivers/input/input.o

File size before:
   text	   data	    bss	    dec	    hex	filename
   2355	    384	      8	   2747	    abb	drivers/input/rmi4/rmi_bus.o

File size after:
   text	   data	    bss	    dec	    hex	filename
   2483	    264	      8	   2755	    ac3	drivers/input/rmi4/rmi_bus.o

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
diff --git a/drivers/input/rmi4/rmi_bus.c b/drivers/input/rmi4/rmi_bus.c
index 1c40d94..213e318 100644
--- a/drivers/input/rmi4/rmi_bus.c
+++ b/drivers/input/rmi4/rmi_bus.c
@@ -55,7 +55,7 @@ static void rmi_release_device(struct device *dev)
 	kfree(rmi_dev);
 }
 
-static struct device_type rmi_device_type = {
+static const struct device_type rmi_device_type = {
 	.name		= "rmi4_sensor",
 	.release	= rmi_release_device,
 };
@@ -134,7 +134,7 @@ static void rmi_release_function(struct device *dev)
 	kfree(fn);
 }
 
-static struct device_type rmi_function_type = {
+static const struct device_type rmi_function_type = {
 	.name		= "rmi4_function",
 	.release	= rmi_release_function,
 };