dt-bindings: Fix array schemas encoded as matrices

The YAML DT encoding has leaked into some array properties. Properties
which are defined as an array should have a schema that's just an array.
That means there should only be a single level of 'minItems',
'maxItems', and/or 'items'.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/20220119015627.2443334-1-robh@kernel.org