ARM: imx_v6_v7_defconfig: Select wireless extensions option

Select CONFIG_CFG80211_WEXT so that wireless can work out of the box
when using userspace tools such as 'iwconfig'.

Generated by manually selecting CONFIG_CFG80211_WEXT and
then running:

make savedefconfig
cp defconfig arch/arm/configs/imx_v6_v7_defconfig

, which results in additional cleanup.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>