arm64: defconfig: Enable Marvell WiFi-Ex USB driver

MBa91xxCA (imx93-tqma9352-mba91xxca.dts) features a soldered,
non-pluggable USB attached WiFi module. lsusb says:
 ID 1286:204e Marvell Semiconductor, Inc. Bluetooth and Wireless LAN Composite Device
Enable the corresponding driver.

To: Shawn Guo <shawnguo@kernel.org>
To: Fabio Estevam <festevam@gmail.com>
To: Sascha Hauer <s.hauer@pengutronix.de>
Cc: imx@lists.linux.dev
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>