phy: rockchip-samsung-dcphy: Add missing assignment

The "ret = " was accidentally dropped so the error handling doesn't work.

Fixes: b2a1a2ae ("phy: rockchip: Add Samsung MIPI D-/C-PHY driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/e64265a4-9543-4728-a49f-ea910fccef7c@stanley.mountain


Signed-off-by: Vinod Koul <vkoul@kernel.org>