rtc: da9063: RTC driver

Add the RTC driver for DA9063.

[akpm@linux-foundation.org: coding-style tweaks]
Signed-off-by: Opensource [Steve Twiss] <stwiss.opensource@diasemi.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Mark Brown <broonie@linaro.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: David Dajun Chen <david.chen@diasemi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>