Since commit 416f0e8056 ("RTC: sa1100: Update the sa1100 RTC driver."),
the last user of .read_callback is gone. It has been 8 years and now new
user appeared. Simply remove it.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Rename core files so there is a clearer separation between the RTC core and
the RTC drivers.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>