arm64: dts: meson: convert meson-sm1-odroid-c4 to dtsi

Convert the ODROID-C4 dts to meson-sm1-odroid.dtsi and C4 board dts in
preparation for adding additional C4 family boards.

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20210202021021.11068-4-christianshewitt@gmail.com