i2c: introduce device_i2c_driver() macro ...

Add macro and dependency to avoid boilerplate code. Since now simple
i2c drivers only have to include the i2c.h header and call the
device_i2c_driver() macro to register a i2c device driver.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

rtc: abracon: Check obtained time for validity ...

Check obtianed time for validity before returning it to the caller
the same way other RTC drivers do.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

rtc: Add Abracon driver ...

This patch adds support for the Abracon ab-rtcmc-32.768khz-eoz9-s3
RTC. The driver can probably support other Abracon RTCs aswell, but this
hasn't been verified.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>