dt-bindings: mfd: maxim,max14577: Convert to dtschema

Convert the MFD part of Maxim MAX14577/MAX77836 MUIC to DT schema
format.  The example DTS was copied from existing DTS
(exynos3250-rinato.dts), so keep the license as GPL-2.0-only.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220215074759.29402-4-krzysztof.kozlowski@canonical.com