sunxi: Added support for Xunlong Orange Pi PC2

sunxi: Added support for Xunlong Orange Pi PC2

CPU: H5 High Performance Quad-core 64-bit Cortex-A53
GPU: Mali450 OpenGL ES 2.0/1.1/1.0, OpenVG 1.1, EGL
Memory: 1GB DDR3 (shared with GPU)
Onboard Storage: TF card (Max. 32GB) / NOR flash(2MB)
Onboard Network: 1000M/100M Ethernet RJ45
USB 2.0 Ports: Three USB 2.0 HOST, one USB 2.0 OTG, HOST mode
role by default in DTS
Buttons: Power Button(SW4) Debug TTL

UART: ..DC-IN..
>[GND][RX][TX] ..HDMI..

Signed-off-by: Antonio Silverio <menion@gmail.com>