hte: handle nvidia,gpio-controller property

The dt binding adds nvidia,gpio-controller property from Tegra234 SoC
onwards to simplify code handling gpio chip search. The gpio chip search
is needed for the AON GPIO GTE instances to map the hardware timestamp
GPIO request (coming from the GPIO framework) to the tegra HTE
providers. The patch also adds new gpio chip match function to match
from the fwnode instead of the gpio controller label. The addition
of the property does not break ABI for the existing Tegra194 code.

Signed-off-by: Dipen Patel <dipenp@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>