staging: hikey9xx: make phy_ops struct const

Fix the following type of checkpatch warning:
"WARNING: struct phy_ops should normally be const"
Signed-off-by: Atul Gopinathan <leoatul12@gmail.com>
Link: https://lore.kernel.org/r/20210209081935.3084-2-leoatul12@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/hikey9xx/phy-hi3670-usb3.c

@@ -585,7 +585,7 @@ static int hi3670_phy_exit(struct phy *phy)
 	return ret;
 }
 
-static struct phy_ops hi3670_phy_ops = {
+static const struct phy_ops hi3670_phy_ops = {
 	.init		= hi3670_phy_init,
 	.exit		= hi3670_phy_exit,
 	.owner		= THIS_MODULE,