dt-bindings: power: add Amlogic Everything-Else power domains bindings

Add the bindings for the Amlogic Everything-Else power domains,
controlling the Everything-Else peripherals power domains.

The bindings targets the Amlogic G12A and SM1 compatible SoCs,
support for earlier SoCs will be added later.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>