ARM: dts: sun8i: h2+: Add Libre Computer Board ALL-H3-CC H2+ ver.

This patch adds a device tree file for the H2+ version of the Libre
Computer Board ALL-H3-CC. It is the same board first introduced in
commit 6ca35864 ("ARM: dts: sun8i: h3: Add dts file for Libre
Computer Board ALL-H3-CC H3 ver."), with the H3 SoC replaced with
the H2+ SoC, and has only two 2Gb DDR3 chips instead of four.

The device tree utilizes the common board design file for ALL-H3-CC,
providing just the model strings and SoC specifics.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>