phy: rockchip: handle clock without enable function

If a clock doesn't supply the enable hook, clk_enable() will return
-ENOSYS.  In this case the clock is always enabled so there is no error
and the phy initialisation should continue.

Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

drivers/phy/rockchip/phy-rockchip-inno-usb2.c

@@ -119,7 +119,7 @@ static int rockchip_usb2phy_init(struct phy *phy)
 	int ret;
 
 	ret = clk_enable(&priv->phyclk);
-	if (ret) {
+	if (ret && ret != -ENOSYS) {
 		dev_err(phy->dev, "failed to enable phyclk (ret=%d)\n", ret);
 		return ret;
 	}