pinctrl: tegra-xusb: Use devm_pinctrl_register() for pinctrl registration

Use devm_pinctrl_register() for pin control registration and clean
the error path.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>