rtc: convert drivers/rtc/* to use module_platform_driver()

rtc: convert drivers/rtc/* to use module_platform_driver()

This patch converts the drivers in drivers/rtc/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <[email protected]>
Acked-by: Mark Brown <[email protected]>
Acked-by: Mike Frysinger <[email protected]>
Acked-by: Guan Xuetao <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Acked-by: Haojian Zhuang <[email protected]>
Cc: Alessandro Zummo <[email protected]>
Cc: Srinidhi Kasagar <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Cc: Ben Dooks <[email protected]>
Cc: John Stultz <[email protected]>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>