ARM: imx_v6_v7_defconfig: Enable TOUCHSCREEN_AD7879

The Computer on module Colibri iMX7S/iMX7D has
an AD7879 touchscreen controller.

This patch enables the TOUCHSCREEN_AD7879 and TOUCHSCREEN_AD7879_I2C
which support the mentioned controller in i2c mode.
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/configs/imx_v6_v7_defconfig

@@ -179,6 +179,8 @@ CONFIG_MOUSE_PS2=m
 CONFIG_MOUSE_PS2_ELANTECH=y
 CONFIG_INPUT_TOUCHSCREEN=y
 CONFIG_TOUCHSCREEN_ADS7846=y
+CONFIG_TOUCHSCREEN_AD7879=y
+CONFIG_TOUCHSCREEN_AD7879_I2C=y
 CONFIG_TOUCHSCREEN_ATMEL_MXT=y
 CONFIG_TOUCHSCREEN_DA9052=y
 CONFIG_TOUCHSCREEN_EGALAX=y