rtc: twl: remove unnecessary messages

The RTC core already prints a message when the RTC is registered and when
registering fails, it is not necessary to have more in the driver.

Link: https://lore.kernel.org/r/20230827221643.544259-2-alexandre.belloni@bootlin.com


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