ARM: dts: aspeed: tiogapass: Add gpio line names

Added GPIO line names for all gpio used in tiogapass platform,
these line names will be used by libgpiod to control GPIOs

Signed-off-by: Vijay Khemka <vijaykhemka@fb.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>