ARM: amlogic: add Banana Pi M5

ARM: amlogic: add Banana Pi M5

Banana Pi BPI-M5 is a credit card format SBC with the following features:
- Amlogic S905X3 quad core Cortex-A55
- Mali-G31 GPU
- 4GB LPDDR4
- 16GB eMMC flash
- 4 USB 3.0
- 1 GbE ethernet
- HDMI output
- 2x LEDS
- SDCard
- 2.5mm Jack with Stereo Audio + CVBS
- Infrared Received
- ADC Button
- GPIO Button
- 40 pins header + 3pins debug header

[narmstrong: add missing CONFIG_SYS_LOAD_ADDR from defconfig]
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>