dt-bindings: rtc: nxp,pcf85063: Convert to DT schema

Convert the NXP PCF85063 RTC binding to DT schema format.

Add 'interrupts' and 'wakeup-source' as this device has an interrupt
which was not documented, but is in use.
'clock-output-names' and '#clock-cells' are added as well, those were
probably missed when adding clkout support in commit 8c229ab6
("rtc: pcf85063: Add pcf85063 clkout control to common clock framework")

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220725071919.25342-1-alexander.stein@ew.tq-group.com