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

doc: Move driver model docs under develop/

These docs are useful for developers, not users. Move them under that
section.

Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>

doc: Move driver model docs under develop/

These docs are useful for developers, not users. Move them under that
section.

Suggested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>