rtc: pcf85063: Add pcf85063 clkout control to common clock framework

The PCF85063 has a configurable clock output signal. Add support for it
using in the CCF.

Signed-off-by: Michael McCormick <michael.mccormick@enatel.net>
Link: https://lore.kernel.org/r/20200124015239.24662-1-michael.mccormick@enatel.net


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