ARM: dts: aspeed: tacoma: Add GPIOs for FSI

GPIO Q7 is no longer used for air/water. It is repurposed on Tacoma to
indicate internal FSI (low) vs cabled (high).

GPIO B0 controls the muxing of FSI to the cable (low) or internal pins
(high).

Acked-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>