pinctrl: tegra: Flush pinctrl writes during resume

This patch adds pinctrl register read to flush all the prior pinctrl
writes and then adds barrier for pinctrl register read to complete
during resume to make sure all pinctrl changes are effective.

Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Link: https://lore.kernel.org/r/1565984527-5272-3-git-send-email-skomatineni@nvidia.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>