phy: rockchip-typec: use correct format for structure description

We get warning with W=1 build:
drivers/phy/rockchip/phy-rockchip-typec.c:360: warning: cannot
understand function prototype: 'struct rockchip_usb3phy_port_cfg '

The 'struct rockchip_usb3phy_port_cfg ' is commented properly but uses
wrong format, so fix that up

Link: https://lore.kernel.org/r/20200708132809.265967-4-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/rockchip/phy-rockchip-typec.c

@@ -347,7 +347,7 @@ struct usb3phy_reg {
 };
 
 /**
- * struct rockchip_usb3phy_port_cfg: usb3-phy port configuration.
+ * struct rockchip_usb3phy_port_cfg - usb3-phy port configuration.
  * @reg: the base address for usb3-phy config.
  * @typec_conn_dir: the register of type-c connector direction.
  * @usb3tousb2_en: the register of type-c force usb2 to usb2 enable.