mx53loco: Remove unneeded gpio_set_value()

There is no need to set the VBUS power enable to 0 first and then to 1.

Set it to 1 in the gpio_direction_output() function.

While at it, use the standard naming convention for the GPIO comment.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>