usb: host: xhci-tegra: use regulator_bulk_set_supply_names()

Use the new regulator helper instead of a for loop.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20191001132333.20146-4-brgl@bgdev.pl


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