misc: add FPC202 dual port controller driver

misc: add FPC202 dual port controller driver

The TI FPC202 dual port controller serves as a low-speed signal aggregator
for common port types such as SFP, QSFP, Mini-SAS HD, and others.

It aggregates GPIO and I2C signals across two downstream ports, acting as
both a GPIO controller and an I2C address translator for up to two logical
devices per port.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>