A 'phandle' type is always a single cell, so 'maxItems: 1' is redundant.

Fixes: 82b96552 ("dt-bindings: nvme: Add Apple ANS NVMe")
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/20220606212230.1360617-1-robh@kernel.org