soc: amlogic: Add Meson6/Meson8/Meson8b/Meson8m2 SoC Information driver

Amlogic SoCs have an information register which contains the SoC type
and revision information.
This patchs adds support for decoding those registers and exposing the
resulting information via the SoC bus infrastructure.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>