USB: PHY: tegra: Call tegra_usb_phy_close only on device removal

tegra_usb_phy_close() is supposed to undo the effects of
tegra_usb_phy_init(). It is also currently added as the USB PHY shutdown
callback, which is wrong, since tegra_usb_phy_init() is only called
during probing wheras the shutdown callback can get called multiple
times. This then leads to warnings about unbalanced regulator_disable if
the EHCI driver is unbound and bound again at runtime.

Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>