ARM: imx_v6_v7_defconfig: Select the Wifi ath10k sdio driver

Select the ath10k sdio driver so that Wifi can work by default on
boards like imx6dl-pico-pi with a QCA9377 chip.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>