ARM: imx_v6_v7_defconfig: Select VF610_ADC

The vf610 adc driver is present on Vybrid, MX6SX, MX6UL and MX7D.

Select it by default.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Acked-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

arch/arm/configs/imx_v6_v7_defconfig

@@ -314,6 +314,8 @@ CONFIG_MXS_DMA=y
 CONFIG_FSL_EDMA=y
 CONFIG_STAGING=y
 # CONFIG_IOMMU_SUPPORT is not set
+CONFIG_IIO=y
+CONFIG_VF610_ADC=y
 CONFIG_PWM=y
 CONFIG_PWM_IMX=y
 CONFIG_EXT2_FS=y