global: Use proper project name U-Boot

Use proper project name in comments, Kconfig, readmes.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/0dbdf0432405c1c38ffca55703b6737a48219e79.1684307818.git.michal.simek@amd.com
diff --git a/doc/board/amlogic/s400.rst b/doc/board/amlogic/s400.rst
index 59dda82..205e7c3 100644
--- a/doc/board/amlogic/s400.rst
+++ b/doc/board/amlogic/s400.rst
@@ -56,7 +56,7 @@
     $ make
     $ export FIPDIR=$PWD/fip
 
-Go back to mainline U-boot source tree then :
+Go back to mainline U-Boot source tree then :
 
 .. code-block:: bash