The binding already lists compatibles and regulators for the AXP806,
but it is missing from the list of supported chips at the beginning.

Add it.

Fixes: 204ae296 ("mfd: axp20x: Add bindings for AXP806 PMIC")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>