dt-binding: memory: pl353-smc: Rephrase the binding

Reword this document before converting it to yaml.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210610082040.2075611-2-miquel.raynal@bootlin.com


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>