phy: samsung: Add support for the Exynos5420 variant of the USB2 PHY

phy: samsung: Add support for the Exynos5420 variant of the USB2 PHY

Exynos5420 differs a bit from Exynos5250 in USB2 PHY related registers in
the PMU region. Add a variant for the Exynos5420 case. Till now, USB2 PHY
worked only because the bootloader enabled the PHY, but then driver messed
USB 3.0 DRD related registers during the suspend/resume cycle.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201120085637.7299-2-m.szyprowski@samsung.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>