dt-bindings: rtc: Remove the PCF8563 from the trivial RTCs

The PCF8563 has a binding of its own, with some, clocks related, additional
properties.

Remove it from the trivial RTC bindings.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://lore.kernel.org/r/20190722140921.22681-1-maxime.ripard@bootlin.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>