Staging: ste_rmi4: constify synaptics_rmi4_platform_data structures

This synaptics_rmi4_platform_data structure is never modified, so declare
it as const.  Others are already const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ste_rmi4/synaptics_i2c_rmi4.c

@@ -870,7 +870,7 @@ static int synaptics_rmi4_i2c_query_device(struct synaptics_rmi4_data *pdata)
  * Descriptor structure.
  * Describes the number of i2c devices on the bus that speak RMI.
  */
-static struct synaptics_rmi4_platform_data synaptics_rmi4_platformdata = {
+static const struct synaptics_rmi4_platform_data synaptics_rmi4_platformdata = {
 	.irq_type       = (IRQF_TRIGGER_FALLING | IRQF_SHARED),
 	.x_flip		= false,
 	.y_flip		= true,