dt-bindings: pinctrl: Remove bindings for Intel Thunderbay pinctrl driver

Remove Thunder Bay specific code as the product got cancelled
and there are no end customers or users.

Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
Link: https://lore.kernel.org/r/20230403120235.939-2-lakshmi.sowjanya.d@intel.com


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