dt-bindings: usb: vialab,vl817: Cleanup compatible, reset-gpios and required

Cleanup by removing unneeded quotes from refs and
add maxItems to reset-gpios and fix the required list.

Fixes: 31360c28 ("dt-bindings: usb: Add binding for Via lab VL817 hub controller")
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230130084744.2539-5-linux.amoon@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>