ARM: dts: at91: sama5d2_ptc_ek: fix vbus pin

The gpio property for the vbus pin doesn't match the pinctrl and is
not correct.

Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Fixes: 42ed5355 "ARM: dts: at91: introduce the sama5d2 ptc ek board"
Cc: stable@vger.kernel.org # 4.19 and later
Link: https://lore.kernel.org/r/20200401221947.41502-1-ludovic.desroches@microchip.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>