usb: phy: tegra: Hook up init/shutdown callbacks

usb: phy: tegra: Hook up init/shutdown callbacks

Generic PHY provides init/shutdown callbacks which allow USB-host drivers
to abstract PHY's hardware management in a common way. This change allows
to remove Tegra-specific PHY handling from the ChipIdea driver.

Note that ChipIdea's driver shall be changed at the same time because it
turns PHY ON without the PHY's initialization and this doesn't work now,
resulting in a NULL dereference of phy->freq because it's set during of
the PHY's initialization.

Acked-by: Peter Chen <peter.chen@nxp.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200106013416.9604-6-digetx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>