ARM: omap2plus_defconfig: Enable EXTCON_USB_GPIO

We need to enable EXTCON_USB_GPIO_USB and not
EXTCON_GPIO_USB.

Fixes: c08a54c0

 ("ARM: omap2plus_defconfig: Enable EXTCON_GPIO_USB")

Reported-by: Nishant Menon <nm@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by-by: Nishanth Menon <nm@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>