ARM: dts: imx6ul: ccimx6ulsom: Add support for wireless SOM variant

The wireless variants of the ConnecCore 6UL SOM include a Qualcomm
QCA6564 wireless chip with dual WiFi and Bluetooth.

Both the ConnectCore 6UL SBC Express and Pro boards fit a wireless SOM.

The Wifi is connected through the SDIO interface on usdhc1 and the
Bluetooth is connected via uart1.

Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Alex Gonzalez <alex.gonzalez@digi.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>