* Add in a default GPIO section for AR91XX_BASE.hints, which doesn't
define the GPIO function masks or any GPIO pines.
* Add in the GPIO line definitions for LEDs and GPIO pins for the
TP-WR1043nd.
I've verified the LEDs work fine using gpioset.
At some point it would be nice to correctly update the bus glue to make
this "correct", including having the DDR flush occur in the right spot
(ie, any AHB interrupt.)