This adjusts the Makefile to use the new option to turn off the
doc builds. It will not cause any problems except a warning
about unused options if combined with a ccache source missing
the upstream patch.
Since a config setting is required to re-enable the doc build this
is equivalent to unconditionally disabling the docs if the config
setting is not created.
Signed-off-by: David Adair <djabhead@aol.com>
2d15468323