rtc: pcf85063: fix pcf85063_clkout_control

rtc: pcf85063: fix pcf85063_clkout_control

[ Upstream commit c2d12e85336f6d4172fb2bab5935027c446d7343 ]

pcf85063_clkout_control reads the wrong register but then update the
correct one.

Reported-by: Janne Terho <janne.terho@ouman.fi>
Fixes: 8c229ab6048b ("rtc: pcf85063: Add pcf85063 clkout control to common clock framework")
Link: https://lore.kernel.org/r/20221211223553.59955-1-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>