usb: chipidea: usb2: constify zynq_pdata

pdata is copied anyway to allow setting device name.
Make the source const.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

drivers/usb/chipidea/ci_hdrc_usb2.c

@@ -28,7 +28,7 @@ static const struct ci_hdrc_platform_data ci_default_pdata = {
 	.flags		= CI_HDRC_DISABLE_STREAMING,
 };
 
-static struct ci_hdrc_platform_data ci_zynq_pdata = {
+static const struct ci_hdrc_platform_data ci_zynq_pdata = {
 	.capoffset	= DEF_CAPOFFSET,
 };