E810-T adapters have two external bidirectional SMA connectors and two
internal unidirectional U.FL connectors. Multiplexing between U.FL and
SMA and SMA direction is controlled using the PCA9575 expander.

Add support for the PCA9575 detection and control of the respective pins
of the SMA/U.FL multiplexer using the GPIO AQ API.
Signed-off-by: Maciej Machnikowski <maciej.machnikowski@intel.com>
Tested-by: Sunitha Mekala <sunithax.d.mekala@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>