Add support for cypress I2C GPIO expanders cy8c9520, cy8c9540 and
cy8c9560. The GPIO expanders feature a PWM mode, thus add it as
pinctrl driver.

The chip features multiple drive modes for each pin when configured
as output and multiple bias settings when configured as input.

Tested all three components and verified that all functionality
is fully working.

Datasheet: https://www.cypress.com/file/37971/downloadSigned-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com>
Link: https://lore.kernel.org/r/20220816054917.7893-3-patrick.rudolph@9elements.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>