arm64: allwinner: h5: add NanoPi NEO Plus2 DT support

Add initial DT for NanoPi NEO Plus2 by FriendlyARM
- Allwinner quad core H5 Cortex A53 with an ARM Mali-450MP GPU
- 1 GB DDR3 RAM
- 8GB eMMC flash (Samsung KLM8G1WEPD-B031)
- micro SD card slot
- Gigabit Ethernet (external RTL8211E-VB-CG chip)
- 802.11 b/g/n WiFi, Bluetooth 4.0 (Ampak AP6212A module)
- 2x USB 2.0 host ports & 2x USB via headers

Signed-off-by: Antony Antony <antony@phenome.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>