dt-bindings: rtc: zynqmp: Add clock information

Added clock information and deprecated calibration support.

Signed-off-by: Srinivas Neeli <srinivas.neeli@xilinx.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220626070817.3780977-1-srinivas.neeli@xilinx.com