drivers/rtc/rtc-ep93xx.c: convert to use module_platform_driver()

Use module_platform_driver() to remove the boilerplate code.

Also, change the probe and remove functions to __devinit/__devexit.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>