GS-King-X is also supported with the beelink-s922x FIP sources and can use
the GT-King defconfig. Add a board document with instructions.
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Link: https://lore.kernel.org/r/20230320114609.930145-33-christianshewitt@gmail.com
[narmstrong: fixed doc build]
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
