ARM: dts: nuvoton: Add Quanta GSJ BMC pinctrl

Add pinctrl definition for the Quanta GSJ BMC machine.

Signed-off-by: Fran Hsu <Fran.Hsu@quantatw.com>
Reviewed-by: Benjamin Fair <benjaminfair@google.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>