mfd: axp20x: Add AXP221/AXP223/AXP809 GPIO cells

These PMICs all contain a compatible GPIO controller.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220616060915.48325-3-samuel@sholland.org