doc: boards: amlogic: add documentation for WeTek Hub and WeTek Play2

Add build instructions for the WeTek Hub and WeTek Play2 boards.

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20230323143142.780306-15-christianshewitt@gmail.com


[narmstrong: fixed doc build]
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>