gpio: tegra: Clean up whitespaces in tegra_gpio_driver

Clean up inconsistent whitespaces and tabs in the definition of
tegra_gpio_driver to make code look better a tad.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>