arm64: defconfig: Enable Marvell WiFi-Ex PCIe driver

Enable the wireless network driver to support the WiFi adapter
present in RK3399 Kevin Chromebooks. Note that this also
enables Bluetooth via USB.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>