The reusable and the no-map property are mutually exclusive.
Clarify this in the documentation.

Acked-by: Grant Likely <grant.likely@arm.com>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Link: https://lore.kernel.org/r/20200910162020.3927-1-xypron.glpk@gmx.de


Signed-off-by: Rob Herring <robh@kernel.org>