ARM: imx_v6_v7_defconfig: Select CONFIG_NOP_USB_XCEIV by default

In order to get USB functionality on mx5 boards, we need to select
CONFIG_NOP_USB_XCEIV option, so let's enable it by default.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/configs/imx_v6_v7_defconfig

@@ -195,6 +195,7 @@ CONFIG_USB_EHCI_MXC=y
 CONFIG_USB_CHIPIDEA=y
 CONFIG_USB_CHIPIDEA_HOST=y
 CONFIG_USB_PHY=y
+CONFIG_NOP_USB_XCEIV=y
 CONFIG_USB_MXS_PHY=y
 CONFIG_USB_STORAGE=y
 CONFIG_MMC=y