rockchip: add evb_rk3229 board

evb_rk3229 is a RK3229 based board, with:
- 8GB eMMC;
- 1GB DDR SDRAM;
- 2 USB2.0 HOST port;
- 1 MAC port;
- 1 HDMI port;
- IR;
- WiFi;

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>