dt-bindings: rtc: nxp,pcf8563: Absorb pcf85263/pcf85363 bindings

The NXP PCF85263/PCF85363 Real Time Clock is very similar to the NXP
PCF8563.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/e4f48d97f0e16d78a796f02b77ea3a0018904185.1623416431.git.geert+renesas@glider.be


Signed-off-by: Rob Herring <robh@kernel.org>