dt-bindings: nvmem: add common definition of nvmem-cell-cells

Linux kernel NVMEM consumer bindings define phandle to NVMEM cells
("nvmem-cells"), thus we also want the common definition of property
defining number of cells encoding that specifier, so the

Suggested-by: Rob Herring <robh@kernel.org>
Reported-by: Michael Walle <michael@walle.cc>
Closes: https://github.com/devicetree-org/dt-schema/pull/89


Reported-by: Rafał Miłecki <zajec5@gmail.com>
Closes: https://lore.kernel.org/linux-arm-kernel/20221121105830.7411-1-zajec5@gmail.com/#r
Closes: https://lore.kernel.org/all/bdf7751b-0421-485d-8382-26c084f09d7d@gmail.com/


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240224114516.86365-5-srinivas.kandagatla@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>