dt-bindings: pinctrl: st,stm32: Correct 'resets' property name

The correct property name for the reset binding is 'resets', not 'reset'.
Assuming actual users are correct, this error didn't show up due to
missing 'additionalProperties: false'. Fix the name and add missing
'additionalProperties'.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220719214955.1875020-1-robh@kernel.org


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