rtc: ds1307: fix data pointer to m41t0

data field points to m41t00, instead it should point to m41t0.
Driver works correctly because on both cases(m41t0 and m41t00) chip_desc
are equal.

Point to right enum m41t0 instead of m41t00.

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>