usb: phy: tegra: Clean up ulpi_phy_power_off

Firstly, the PHY's clock needs to unprepared to keep prepare count
balanced. Secondly, downstream code suggests that reset is synchronous
and thus it should be asserted before disabling clock.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20200106013416.9604-4-digetx@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>