pinctrl: tegra: Convert to devm_ioremap_resource

Using the new devm_ioremap_resource() we can greatly simplify resource handling.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>