Documentation: usb: phy: nop: Fix the description of 'vcc-supply'

Since bd27fa44 ("usb: phy: generic: Don't use regulator framework for
RESET line") we no longer model the reset line as a regulator supply, so
adapt the documentation accordingly.
Acked-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt

@@ -13,7 +13,7 @@ Optional properties:
 - clock-frequency: the clock frequency (in Hz) that the PHY clock must
   be configured to.
 
-- vcc-supply: phandle to the regulator that provides RESET to the PHY.
+- vcc-supply: phandle to the regulator that provides power to the PHY.
 
 - reset-gpios: Should specify the GPIO for reset.