gpio: board.txt: Fix the gpio name example
gpio: board.txt: Fix the gpio name example

As explained in this file:

"GPIOs mappings are defined in the consumer device's node, in a property named
<function>-gpios"

So fix the example to match the convention.

Signed-off-by: Fabio Estevam <679188261afeb60eb822cd934fd7b46a48ddd743@freescale.com>
Acked-by: Alexandre Courbot <301cd6a3ea50a894b4b51e385c5eb12b9a4ffc0c@nvidia.com>
Signed-off-by: Jonathan Corbet <b2ce64d5587c02f12e367eac59751145a0660c51@lwn.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs