phy: exynos5-usbdrd: Calibrating makes sense only for USB2.0 PHY

PHY calibration is needed only for USB2.0 (UTMI) PHY, so skip calling
calibration code when phy_calibrate() is called for USB3.0 (PIPE3) PHY.

Fixes: d8c80bb3 ("phy: exynos5-usbdrd: Calibrate LOS levels for exynos5420/5800")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200708133800.3336-1-m.szyprowski@samsung.com


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